Spicy Chocolate Caramel Sandwich Cookies

Ingredients

11.25 oz all-purpose flour (2.5 cups)
2.25 oz unsweetened cocoa powder (3/4 cup)
1 tsp baking soda
1/4 tsp salt
1/2 tsp black pepper
1 tsp cayenne powder (or less—to taste)
2 tsp ground cinnamon
10 oz unsalted butter at room temperature
7 oz granulated sugar (1 cup)
5.6 oz packed brown sugar (3/4 cup)
2 eggs
2 tsp vanilla

FOR THE SOFT CARAMEL:
2 oz water (1/4 cup)
5 1/2 oz light corn syrup (1/2 cup)
14 oz granulated sugar (2 cups) plus more for rolling
12 oz heavy cream (1 1/2 cups)
4 oz unsalted butter cubed (1/2 cup)
1 tsp sea salt
1 tsp vanilla extract

FOR THE BUTTERCREAM:
12 oz powdered sugar (3 cups, sifted after measuring)
4 oz unsalted butter at room temperature (1/2 cup, or 1 stick)
2 tbsp milk plus more if necessary
1 tsp vanilla extract (or other flavoring extracts)
1/4 tsp salt
3/4 tsp ground cinnamon

TO ASSEMBLE:
1 1/4 lbs chocolate candy coating or semi-sweet chocolate
Cocoa nibs, sprinkles, chopped nuts, or other toppings of choice

Directions

Sift together the flour, cocoa, baking soda, salt, pepper, cayenne, and cinnamon into a large bowl, and set aside for now.
Combine the butter and both sugars in the bowl of a large stand mixer fitted with a paddle attachment. Cream them together on medium speed for 1-2 minutes, until fluffy and well-combined. Add the eggs one at a time, mixing well after each addition, then add the vanilla. Finally, turn the mixer speed to low and add the flour, mixing until almost all of the streaks are gone. Stop the mixer and finish mixing by hand, scraping the bottom and sides of the bowl with a rubber spatula.
Wrap the dough in cling wrap and refrigerate for at least an hour, until it’s firmed up enough to easily roll into balls. Preheat the oven to 350 F.
Line your baking sheets with parchment paper. Take a small scoop of dough (only about 1 inch wide!) and roll it into ball, then roll the dough in granulated sugar. Place the dough ball on the baking sheet, and use the bottom of a glass to flatten it into a disc. Repeat with remaining dough—you should get about 72 small cookies from this batch. Bake the trays for 8-9 minutes, until they’ve spread and are set around the edges but still soft in the middle. Let cookies cool completely before assembling the sandwich cookies.
TO MAKE THE SOFT CARAMEL:
Combine the water, light corn syrup, and granulated sugar in a large saucepan. Place the pan over medium heat, and stir while the sugar dissolves. Brush down the sides of the pan occasionally with a wet pastry brush to remove stray sugar crystals. Bring the mixture to a boil, then stop stirring and insert a candy thermometer. Allow the sugar to cook, undisturbed, until it is a medium amber color and reaches 330 F on the thermometer.
While the sugar cooks, combine the cream, butter, and salt in a medium saucepan. Place the pan over medium heat and bring the cream to a simmer. Once simmering, remove the pan from the heat and set aside.
When the caramel has reached 330 F, add the hot cream to the pan carefully—it will splutter, boil, and steam quite a bit, so stand back from the pot! Stir the cream and caramel together. Continue to cook the mixture, stirring occasionally, until it reaches 234 F.
Remove the pan from the heat and stir in the vanilla extract. Pour the caramel into a heatproof bowl or baking pan. Let it sit at room temperature until it is entirely cool and thickened. It should have a texture that is easily scoopable with a spoon, but it should mostly hold its shape on the spoon and not be too runny. The caramel can be made in advance and kept at room temperature for a week before using. If making it in advance, simply cover the bowl or pan of caramel with cling wrap until ready to use.

TO MAKE THE BUTTERCREAM:
Place all of the ingredients in the bowl of a large stand mixer fitted with a paddle attachment. Mix on low speed until the sugar is moistened. Scrape down the sides of the bowl, then beat again on medium speed until light and fluffy, 2-3 minutes. You can add more milk or sugar, if desired, to get the consistency you want.

TO ASSEMBLE:
Transfer the buttercream to a piping bag fitted with a large round tip. Place one cookie, bottom-up, on your work surface, and pipe a ring of buttercream along the outside edge. Take a candy scoop or teaspoon and scoop up a small ball of caramel. Place it in the middle of the cookie and gently press a second cookie on top, pressing down so that the caramel is pushed to the edges of the buttercream. Repeat with the remaining cookies until you have 36 sandwich cookies assembled. Refrigerate to firm up the buttercream, about 30 minutes.
Melt the chocolate candy coating or semi-sweet chocolate in the microwave. (I recommend either using candy coating, or tempering the chocolate following these directions, since regular melted chocolate can get soft, sticky, or bloomed at warm room temperature.) Dip half of a cookie in the chocolate, and let the extra drip back into the bowl. Set the dipped cookie back on a waxed paper-covered baking sheet, and while the chocolate is still wet, sprinkle the top with cocoa nibs, sprinkles, crushed nuts, or your toppings of choice. Repeat until all of the cookies are dipped. Refrigerate the trays briefly to set the chocolate, then serve! For the best taste and texture, serve these cookies at room temperature.