Preheat oven to 350°F and spray 9x13 baking dish with nonstick cooking spray
In a microwave safe dish melt the butter. Microwave for 30 seconds, stir, and repeat until the butter is completely melted.
Stir cocoa powder into melted butter making sure there are no clumps. Set aside.
While butter mixture is cooling, in a separate small bowl combine the flour, baking powder, and salt. Set aside.
In a stand mixer, or using a hand mixer, mix together the butter mixture (it’s okay if it’s still warm), sugar, espresso powder, and vanilla. Then add the eggs one at a time, letting each egg become fully incorporated into the batter before adding the next.
By hand, with a large rubber spatula or mixing spoon, fold in the flour mixture. Folding in the flour will help the brownie batter keep the air in it.
Pour into the prepared baking dish then pour chopped candy over the top.
Bake for 25-30 minutes or until a toothpick comes out clean.
Repeat steps 1-8 for the second batch of brownies.