These cookies start with a Betty Crocker™ Devil's Food Cake Mix and bake up thick, soft, and fudgy. Topped with rich chocolate buttercream frosting, crushed cookies, and gummy worms for a spooky touch.
Heat oven to 350°F. Line two large baking sheets with parchment paper; set aside.
In a large mixing bowl, whisk together the melted butter, eggs, granulated sugar, and 1 teaspoon vanilla until smooth and slightly thickened.
Add the dry cake mix, baking cocoa, cornstarch, and flour. Using a silicone spatula or electric mixer on low speed, mix until everything is fully combined and no streaks of dry ingredients remain. The dough will be thick and sticky, similar to brownie batter but sturdy enough to scoop.
Using a 3-tablespoon cookie scoop, drop dough into 13 equal portions onto the prepared baking sheets, leaving about 2 inches of space between each cookie to allow for spreading.
Bake for 9 to 10 minutes or until the edges look set but the centers still appear soft and slightly glossy. (They’ll continue to firm up as they cool, keeping that fudgy texture.) Gently flatten the tops of the cookies with a flat-bottomed cup. Cool on the baking sheets for 5 minutes; transfer to a cooling rack to cool completely.
Meanwhile, place the chopped chocolate in a heat-safe bowl; set aside. In a small saucepan, heat the heavy cream over medium heat until just beginning to steam and small bubbles form around the edges—don’t let it boil.
Pour the hot cream over the chocolate; let stand 1 minute. Slowly stir the mixture from the center outward until the chocolate is completely melted and mixture is smooth and glossy. Set aside to cool slightly (mixture should be fluid but no longer hot).
In a large bowl, beat the butter on medium-high speed with an electric mixer for about 2 minutes until light and creamy.
Gradually add the powdered sugar, about 1/2 cup at a time, mixing on low speed until blended. Add the cooled chocolate mixture, salt, and 1/2 teaspoon vanilla, then increase to medium-high speed and beat for 1 minute until the frosting is silky and spreadable. If it’s too soft, refrigerate for 10 minutes.
Spread a thick layer of frosting on top of each cooled cookie.
Sprinkle crushed cookies over the frosting to create a “dirt” layer. To decorate, press gummy worms, candy bones, or any spooky Halloween candy gently into the frosting.
