National Chocolate Chip Cookie Day is the perfect excuse to turn on the oven and bake something sweet.In honor of the celebration, Milk Bar founder Christina Tosi and founder of The Hungry Gnome and author of "The Scone Queen Bakes," Danielle Sepsy joined "Good Morning America" on Tuesday to share four of their favorite cookie recipes.Tosi brought two of Milk Bar's signature treats: her Cornflake Chocolate Chip Marshmallow Skillet Cookie and her Chocolate Chip & Chunk Cookie.Chef Danielle Sepsy, a cookbook author and founder of The Hungry Gnome Bakery.Courtesy of Scott SemlerMeanwhile, Sepsy shared two recipes perfect for home bakers: her Junk Drawer Cookie, packed with a mix of sweet and salty ingredients, and The Dans' Cookie (Peanut Butter Chocolate Chunkers).Whether you're baking for friends and family or simply treating yourself, these four recipes are a delicious way to celebrate the sweet holiday.Find the full recipes below.Cornflake Chocolate Chip Marshmallow Skillet CookieYield: Makes one 9- or 10-inch skillet cookieIngredients2 sticks unsalted butter, at room temperature1 1/4 cups granulated sugar2/3 cup light brown sugar1 egg1/2 teaspoon vanilla extract1 1/2 cups flour1/2 teaspoon baking powder1/2 teaspoon baking soda1 teaspoon kosher salt3 cups Cornflake Crunch, plus some extra for decor (recipe follows)2/3 cup mini chocolate chips, plus some extra for decor1 1/4 cups mini marshmallows, plus some extra for decorDirectionsHeat the oven to 350 degrees with your 10-inch cast-iron skillet in it.Combine the butter and sugars in the bowl of a stand mixer fitted with the paddle attachment and cream together on medium-high for 2 to 3 minutes. Scrape down the sides of the bowl, add the egg and vanilla, and beat for 7 to 8 minutes. Reduce the mixer speed to low and add the flour, baking powder, baking soda, and salt. Mix just until the dough comes together, no longer than 1 minute. (Do not walk away from the machine during this step, or you will risk overmixing the dough.) Scrape down the sides of the bowl with a spatula.Still on low speed, paddle in the cornflake crunch and mini chocolate chips just until they’re incorporated, no more than 30 to 45 seconds. Paddle in the mini marshmallows just until incorporated.Carefully remove the skillet from the heat and spread the dough evenly to the edges. Bake until the cookie is golden brown and just set in the center, 18 to 20 minutes.Cool at room temperature on a towel for 10 minutes. While still warm, use a spatula to divide the skillet cookie into slices.Then melt the chocolate and decorate the edges of your skillet cookie with additional cornflake crunch, mini chocolate chips and mini marshmallows as you like. Cornflake Crunch Yield: Makes a little more than 3 cupsIngredients5 cups cornflakes1/2 cup milk powder3 tablespoons sugar3/4 teaspoon kosher salt9 tablespoons butter, meltedDirectionsHeat the oven to 275°F.Pour the cornflakes in a medium bowl and crush them with your hands to one-quarter of their original size. Add the milk powder, sugar, and salt and toss to mix. Add the butter and toss to coat. As you toss, the butter will act as glue, binding the dry ingredients to the cereal and creating small clusters.Spread the clusters on a parchment- or Silpat-lined sheet pan and bake for 20 minutes, at which point they should look toasted, smell buttery, and crunch gently when cooled slightly and chewed.Cool the cornflake crunch completely before using in the recipe above.Tips from Tosi1. Don't rush the creaming step: cream the butter and sugar well for a lighter, chewier cookie.2. Don't overmix after adding the flour -- mix just until combined.3. Make sure to preheat the skillet for crisp, caramelized edges.4. Pull the cookie skillet out of the oven when the center is just set -- it will continue baking as it cools!Chocolate Chip & Chunk Cookies Yield: Makes one dozen cookiesIngredients1 stick butter, super soft1/2 cup light brown sugar1/3 cup + 1 Tablespoon sugar1 ea egg2 teaspoons vanilla extract1 1/2 cups oat flour2 tablespoons milk powder1 teaspoon baking powder3/4 kosher salt1/2 cup chocolate chunks1/2 cup chocolate chipsOptional: Make it a Compost Cookie by adding your favorite pantry snacks to the mix!Summer Compost versionIngredients1/2 cup Rainbow sprinkle nonpareils1/2 cup Mini marshmallows1/2 cup Mini pretzels1/3 cup freeze-dried strawberriesDirectionsHeat the oven to 350°F and pan spray or line two half-sheet pans with parchment or silicone baking mats.In a large bowl, using a sturdy spatula, mix together the butter and sugars, flexing your muscles for about 2 minutes, until they are fully combined. Add the egg and vanilla extract and stir until combined and fluffy, about 1 minute.Measure the oat flour, milk powder, baking powder and salt into the mixing bowl. Toss only the dry ingredients on top together with the spatula first, before truly stirring them into the wet ingredients below. Mix all until just combined. Stir in chocolate chips and chunks (and optional: Make it a "Compost Cookie" by adding any other fun salty or sweet ingredients you like!)Scoop or roll your dough into balls (½ cup or 2 ¾ ounce ice cream scoop in size) and place 2 to 3 inches apart on your prepared sheets. Bake at 350°F for 8 to 10 minutes, until the edges of the cookies are golden brown. Cool cookies completely on trays. Tips from TosiFor summer compost cookies:1. Use super-soft (not melted) butter for the perfect texture.2. Milk powder adds rich, caramelized flavor and extra chew.3. Bake until the edges are golden and the centers are still soft.4. Have fun with mix-ins, both sweet and savory, to help tell your flavor story!Junk Drawer Cookies"Be sure to use kettle-cooked chips as they will retain their crunch even if you freeze the cookie dough balls and bake them off another day," Sepsy writes. "Trust me, this is one of those treats you will always want to have on hand for 'emergency cravings,' so make the dough balls, place them in plastic bags, freeze them, and then bake them off as needed."Popular ReadsYield: Makes 12 to 14 cookiesIngredients1/2 cup packed dark brown sugar2 tablespoons granulated sugar8 tablespoons (4 ounces / 1 stick) unsalted butter, at room temperature1 1/4 cups cake flour (not self-rising)1/2 teaspoon baking soda1/2 teaspoon fine table salt1/4 teaspoon ground cinnamon1/3 cup dry vanilla instant pudding mix (I prefer Jell-O)1 large egg, at room temperature1 teaspoon pure vanilla extract3/4 cup bittersweet chocolate chips (I like Ghirardelli); see Tip1/3 cup milk chocolate chips1/3 cup white chocolate chips1/3 cup sweetened coconut flakesHeaping 1/3 cup crushed salted kettle-cooked potato chips1/4 cup toffee bits, such as HeathFlaky sea salt (optional), for toppingDirectionsPreheat the oven to 375°F (or 350°F on the convection setting). Line a cookie sheet with parchment paper.In a stand mixer fitted with the paddle, blend together the brown sugar, granulated sugar, and butter until light and creamy, about 3 minutes.Meanwhile, in a separate bowl, stir together the cake flour, baking soda, fine salt, and cinnamon. Set aside.Add the dry pudding mix, egg, and vanilla to the butter/sugar mixture and beat until combined. Scrape down the sides of the bowl to ensure everything is incorporated evenly and blend again on high for another 3 minutes.On low speed, gradually beat the flour mixture into the butter mixture until everything is incorporated. Scrape down the sides of the bowl to make sure it is evenly incorporated.On low speed (or by hand with a wooden spoon), mix in all the chocolate chips, the coconut flakes, potato chips, and toffee bits until just combined. Do not overmix.Using a cookie scoop or a spoon, drop 2-tablespoon balls of dough onto the lined cookie sheet, spacing at least 1 inch apart in case they spread slightly. You want the dough to be in a fairly round, high mound before baking to ensure it gets a nice chewy consistency after baking. If you’d like an extra salty finish, sprinkle a few flakes of sea salt on top of each ball of dough. Transfer to the oven.Bake for 10 minutes. Then, with oven mitts on, carefully rap/bang the pan on the counter to release the air and to assist with spreading slightly. Rotate the pan front to back, return to the oven, and bake for 2 to 3 minutes, until the edges are golden but the cookies are still a bit gooey and soft in the center.Let them cool slightly on the pan before serving. They can be enjoyed warm or cold, they will be soft and chewy regardless!Tips from SepsyFor the chocolate chips:1. You can just use one single type of chocolate chip instead of the three different types called for. Or split the amounts between only two types of chips!For the junk drawer cookie:1. Use cake flour instead of all-purpose for a softer cookie that stays soft for days.2. Adding a little pudding mix to your dough adds to the soft, chewy texture.3. Use a combination of different types of chocolate for a nice differentiation in texture and sweetness.4. Play around with different salty and sweet mix-ins. Perhaps try peanut butter chips or cups, raisins, Cornflakes, pecans, chopped graham crackers or even salted nuts.The Dans' CookiesThe Dans' Cookie.Courtesy of Nico Schinco"This thick, chewy, yet pleasantly dense cookie has all of Dan's favorite flavors and textures, including rich, creamy chocolate; nutty peanut butter chips; and crunchy, salty pretzels," Sepsy writes. "These cookies are strategically made super thick and large to give them the perfect texture and a real WOW presentation."Yield: Makes 8 giant (4-inch) cookiesIngredients8 tablespoons (4 ounces /1 stick) cold unsalted butter, cut into small cubes1/4 cup vegetable shortening, such as Crisco1 cup packed dark brown sugar1/2 cup granulated sugar2 teaspoons pure vanilla extract2 tablespoons creamy peanut butter (I prefer Skippy; do not use natural)2 large eggs2 3/4 cups all-purpose flour1/2 teaspoon baking powder3/4 teaspoon fine table salt1/8 teaspoon ground cinnamon3/4 cup semisweet chocolate chips3/4 cup peanut butter chips3/4 cup roughly chopped hard pretzels, such as Snyder’s Olde Tyme or sourdoughDirectionsIn a stand mixer fitted with the paddle, beat together the butter, shortening, brown sugar, and granulated sugar until light and creamy, about 3 minutes.Add the vanilla and peanut butter and beat until just combined. Add the eggs one at a time, beating to just combine after each addition.In a separate bowl, stir together the flour, baking powder, salt, and cinnamon.On low speed, gradually beat the flour mixture into the butter/sugar mixture, scraping down the sides of the bowl to make sure all ingredients are evenly incorporated.On low speed (or by hand with a wooden spoon), stir in the chocolate chips, peanut butter chips, and pretzels until just combined. Do not overmix.Place a long sheet of plastic wrap on the counter, scoop the dough into the plastic wrap, and use floured hands to form the dough into a log shape about 12 inches long and 3 inches in diameter. Roll it tightly in the plastic wrap. Gently place the log on a pan or plate and refrigerate for at least 2 hours or overnight.When ready to bake, preheat the oven to 375°F (or 350°F on the convection setting). Line two cookie sheets with parchment paper.Using a sharp knife, cut the log into 8 rounds about 1½ inches thick and place them on the lined cookie sheets about 21/2 inches apart. Transfer to the oven.Bake for 11 to 13 minutes, until golden brown on the edges but still soft in the center.Let the cookies cool on the pans.STORAGE: Store in an airtight container or tin or wrapped in parchment paper and then aluminum foil at room temperature for up to 5 days.Tips from Sepsy1. Using a combination of butter and shortening helps get you a softer texture but maximum flavor. Butter = flavor and shortening and oils = softer texture.2. Don't use natural peanut butter in this application as it is too oily and may prevent the dough from coming together properly.3. Use hard sourdough-style pretzels in the dough as they retain their crunch.4. You can freeze your dough log for several months, then just thaw slightly, slice, and bake as needed!5. To prevent cookies from spreading too much, raise your oven temperature.'GMA' kitchen picksBy clicking on these shopping links, visitors will leave ABCNews.com and Goodmorningamerica.com, and these e-commerce sites are operated under different terms and privacy policies. ABC will receive a commission for purchases made through these links. SOME PRICES ARE DYNAMIC AND MAY CHANGE FROM THE DATE OF PUBLICATION. Have questions about ordering or a purchase? Click here.You can never go wrong with a practical (and delicious!) gift like nice olive oil from Graza.