Preheat oven according to the directions on the brownie box.
Add the brownie mix to a large mixing bowl, then add the Diet Coke. Use a spoon and stir it 50 strokes.
Spray an 8x8 baking ban with no-stick cooking spray, then and the brownie batter. Put it in the oven 28-32 minutes, or until a toothpick inserted in the center comes out clean.
Let the brownies cool completely.
Use a 1 1/2 inch circle cookie cutter to cut out 20 brownies.
Use a knife to cut each brownie in half horizontally.
Add the bottom half of the brownies to a mini muffin pan.
Add a small spoonful of ice cream to each brownie, then cover it with the brownie top.
Cover the brownies and put in the freezer for at least 1 hour. Then, enjoy!