Preheat the Oven: Set your oven to 350°F and line a couple of baking sheets with parchment paper to prevent sticking.
Mix the Dry Ingredients: In a large bowl, whisk together the chocolate cake mix and baking powder.
Add Wet Ingredients: Pour in the vegetable oil and crack the eggs into the bowl. Using a sturdy spoon, mix everything together until well combined. The dough will be very thick.
Shape the Cookies: Use a small cookie scoop to scoop out a level portion of cookie dough. Place the dough balls on the prepared baking sheet, about 2 inches apart, as they will spread while baking.
Bake: Put the cookies in the preheated oven and bake for 8-10 minutes. The cookies should be set around the edges but still soft in the center. Allow them to cool for a few minutes on the baking sheet before transferring them to a wire rack to cool completely.
Heat Butter, Cream and Cocoa: While the cookies are cooling, melt butter in a saucepan over medium heat. Pour in the heavy cream and cocoa powder, and stir until everything is combined well and smooth.
Mix in Vanilla and Powdered Sugar: Remove the saucepan from the heat. Whisk in the vanilla extract then gradually whisk in the powdered sugar until the icing is dissolved, smooth and spreadable. If the icing is too thick, you can add a little more cream, a teaspoon at a time, until you reach the desired consistency.
Add Pecans: Add half of the chopped pecans to the icing and mlx until fully combined.
Ice the Cookies: Work quickly to evenly spread about a tablespoon of chocolate icing generously over the top of each cooled cookie.
Add Pecans: While the icing is still wet, sprinkle the remaining 1 cup of chopped pecans evenly over the cookies, pressing them lightly into the icing to ensure they stick.
Let Set: Allow the icing to set before serving. This usually takes about 20-30 minutes.
Notes: If the chocolate icing cools and gets too thick as you’re icing the cookies, place the pan back on the stovetop over very low heat and stir to keep it spreadable.