In a medium bowl, sift the flour and cocoa powder. Add baking soda, baking powder, and salt. Set aside.
1 1/3 cup All-purpose flour, 1/4 tsp Baking soda, 1/4 tsp Baking powder, 1/4 cup Unsweetened cocoa powder, 1/2 tsp Salt
In a large bowl, add the melted butter (it needs to be cooled to room temperature), brown sugar, white sugar, vanilla, egg and egg yolk.
1/2 cup Unsalted butter, 3/4 cup Brown sugar, 1/4 cup White granulated sugar, 2 tsp Pure vanilla extract, 1 Large egg, 1 Egg yolk
Add the dry ingredients and use a rubber spatula to mix until just combined.
Preheat the oven to 350°F. Line two cookie sheets with parchment paper. Let the dough sit for 10 minutes while the oven preheats. This allows the gluten to absorb into the wet ingredients. Unwrap the Hershey kisses, place them in the bowl in the freezer.
20 Hershey's Kisses Hot Cocoa Chocolates
Use a small cookie scoop and scoop the cookie dough. Pour the sugar into a bowl and roll the cookie dough balls in the sugar. Place 12 cookie dough balls per cookie sheet. Take the 20 marshmallows and cut them horizontally, I used kitchen scissors. Set aside.
10 Marshmallows, 1/3 cup White granulated sugar
Bake one cookie sheet at a time. Bake for 6 minutes. Top each cookie in the middle with a marshmallow bake for another 2-3 minutes.
Let the cookies sit on the hot pan for 2 minutes before transferring to a cooling rack. Once they are on the cooling rack top them with Hershey's Kisses. Once cool it can be served.