Preheat oven to 350 degrees F.
Coat twelve 2 1/2" muffin cups with nonstick cooking spray, set aside.
In a large bowl, slightly beat egg.
Add brownie mix, 1/2 can of the cherry pie filling and butter pieces. Stir until well blended.
Stir in walnuts.
Scoop 2 heaping tablespoons of the mixture into each muffin cup. Each cup should be roughly 2/3 full.
Bake for 15 minutes.
Remove from the oven and chill in the refrigerator for 5 minutes. Do not remove the brownie cups from the pan.
Remove from the refrigerator and create a sunken down area in the middle of each brownie cup using the back of a spoon.
Fill each sunken center with 1 tablespoon of the cherry pie filling.
Return to the oven and bake for 12 - 15 more minutes.
After baking, completely cool on a wire rack before removing the brownies from the muffin tin.
To remove the brownies from the muffin cups, run a sharp knife completely around the edge of each one and gently lift the brownie out of the cup. Do not turn the muffin pan upside down to remove the brownies.
To serve - top each brownie with some of the frozen whipped desert topping and dust with unsweetened cocoa.
Yield: 12 - 18 brownies