S'more Thumbprint Cookies

I have to be honest with you, I'm not sure what season s'mores truly belongs in. So many s'mores-inspired recipes pop up in the summer, but my vote is fall. There's nothing quite like a bonfire during a chilly autumn evening. And no fire is complete without smoke-scented clothing and a freshly toasted s'more. 

Out of all the cookies I've made recently, these are my absolute, without-a-doubt, #1 favorite. I've made them several times and just can't get enough of their deep, chewy chocolate base and gooey, toasted marshmallow topping. There's also graham cracker crumbs the dough is rolled in, which solidifies their "s'more" status.

The cookie recipe has some unusual ingredients: corn syrup and egg whites, rather than full eggs. I'm assuming these two are the main contributors to the final product's chewy-fudgy, yet soft texture. I don't think I've ever had a chocolate cookie quite like this! They stay soft for several days...but why in the world would you let them sit that long?! The melted marshmallows are screaming to be eaten almost immediately after they are removed from being broiled.

Important notes!!! Homemade marshmallows are optional. Slightly undercooking the cookies is so not. And make sure you let them cool for at least 3 minutes before digging in or you'll risk them falling apart. Not that messy isn't implied when the name "s'mores" is thrown out...

S'more Thumbprint Cookies

Cookie base adapted from Cook's Illustrated Cookbook (via here)

Servings: 12-16 cookies

1 1/2 cup (7.5 oz) all purpose flour
3/4 cup (2.25 oz) dutch processed cocoa powder
1/2 tsp baking soda
1/4tsp + 1/8 tsp salt
1/2 cup dark corn syrup
1 large egg white
1 tsp vanilla
12 tbsp unsalted butter, softened
1/3 cup (2.33 oz) packed dark brown sugar

1/3 cup (2.33 oz) granulated sugar

1/2 cup graham cracker crumbs

1/2 batch homemade marshmallows or 8 jumbo store-bought marshmallows

• In a medium bowl, combine flour, cocoa powder, baking soda, and salt. In a separate small bowl, whisk corn syrup, egg white, and vanilla together. Set both bowls aside.
• In the bowl of a stand mixer, beat butter and sugars at medium-high speed until light and fluffy (2-3 minutes). Reduce speed to low and add corn syrup mixture. Beat until fully incorporated, making sure to scrape down the bowl with a rubber spatula as needed. Add flour mixture and mix on low until just incorporated and no streaks of flour remain (about 30 seconds). Cover dough and refrigerate dough for 30 minutes to an hour, or until slightly firm and easy to work with.
• Adjust oven racks to upper and middle positions and preheat oven to 375 degrees*. Prepare a baking sheet with parchment paper or baking mat. Place 1/2 cup graham cracker crumbs in shallow baking dish or pie plate. If you are using store-bought marshmallows, prepare them by cutting the cylinders in half, long-ways. If using homemade, cut into small rounds (I used the cap of a cocktail shaker).
• Remove dough from fridge and divide into portions of about 1.5-2 tablespoons (I used a medium cookie dough scoop). Roll between hands into balls, then them in the crumbs to coat**. Place dough balls 2 inches apart on the prepared cookie sheets. Bake until cookies are puffed and cracked and edges have begun to set---cookies should still look raw between cracks---8 to 10 minutes. Do not over bake! 
• Immediately remove baking tray and put oven on "high" broiler setting. Using your thumb, make a wide indentation in the center of each cookie and place a prepared marshmallow piece in each. Return to oven on the upper rack; and allow the marshmallows to toast for about 1 minute. (There may be some smoke when you open the oven to remove the cookies; be prepared with an overhead hood/fan, etc.)
• Remove from oven, and let cookies cool on baking sheets for 5 minutes. Transfer cookies to a wire rack and let cool to room temperature. Repeat with the remaining dough balls. Cookies can be stored in an airtight container at room temperature for up to 5 days.

*Although not necessary, I recommend that you stop here and refrigerate the dough in balls overnight for best results.

**Stop here if you plan to refrigerate overnight or freeze dough for later.