Ingredients

• 1/2 cup butter
• 1/2 cup sugar
• 1/2 cup brown sugar
• 1 large egg
• 1 tsp vanilla
• 1 1/2 cups flour
• 1/4 cup unsweetened cocoa powder
• 1/2 tsp baking soda
• 1/2 tsp baking powder
• 1/2 tsp salt
• 1/2 cup milk-chocolate chips
• 1/2 cup semisweet chocolate chips

Directions

Heat oven to 350°F. Cream the butter and sugars in a large bowl. Add the egg and vanilla. Sift together the flour, cocoa, baking soda, baking powder, and salt. On low speed, add the dry mixture to the butter mixture. Beat until fully incorporated. Fold in the chocolate chips.

Form the dough into approximately 1 1/2-inch balls. Place on parchment-lined baking sheets, 2 inches apart.

Bake until the centers are just set, about 12 minutes. Let cool on sheets for 5 minutes, then transfer to wire racks.