For Marshmallow Fluff

• In a medium saucepan, combine the sugar, water, and corn syrup. Heat until the syrup reaches 240 degrees.
• Meanwhile, in the bowl of a stand mixer with the whisk attachment, whip the egg whites until foamy, then add the salt and cream of tartar. Whip until soft peaks.
• When the syrup reaches 240 degrees, remove from heat and with the mixer on low, slowly pour the syrup into the egg whites. 
• Whip until stiff peaks, then add the vanilla bean paste and mix until combined.
• *The fluff will be easier to work with when chilled, so pop it in the fridge in an airtight container while you make the cookie dough.

For S’mores Cookies

• In the bowl of a stand mixer with the paddle attachment, cream the butter and sugars for 5 minutes, scraping down the bowl as needed.
• Add the egg, egg yolk, and vanilla. Mix for another 3 minutes, until thick.
• In a separate bowl, whisk together the flour, cornstarch, baking powder, baking soda, and salt.
• Add the dry ingredients to the mixer and mix just until combined, leaving a few streaks of flour to ensure that you don’t over mix. 
• Fold in the chocolate chips and graham cracker crumbs.
• Use a large cookie scoop to scoop the cookie dough into 5 oz cookies. I used my 2.5 oz scoop and scooped twice per cookie!
• Chill the dough for 20-30 minutes, just until chilled enough to handle.
• Press the dough flat into your hand and use your thumb to make a well in the center. Use a 1 TBSP scoop with a trigger to scoop the marshmallow fluff into the center. Fold the cookie dough up and around the marshmallow fluff. Leave some of the marshmallow fluff peaking out the top.
• Sprinkle with extra graham cracker crumbs and a chunk of milk chocolate.
• Chill for at least one hour, up to overnight.
• Preheat the oven to 350 degrees and line a cookie sheet with parchment paper.
• The cookies are huge and will spread, so bake 3 at a time and leave plenty of room in between.
• Bake for 12 minutes. They will seem under done in the center, but will set up as they cool.
• Use a large round cookie cutter to swirl around the hot cookie right as it comes out of the oven for a perfectly round cookie.
• Let chill on the cookie sheet for at least 10 minutes before transferring to a cooling rack.