Preheat oven to 350°F. Prepare 13 in. x 9 in. pan with vegetable pan spray.

In large saucepan, melt butter, brown sugar, cocoa powder and salt over medium heat, stirring often until completely liquid and very warm to the touch. Remove saucepan from heat. Quickly add eggs and vanilla and stir until combined. Add flour and baking powder; stir until batter is very shiny and combined. Mixture will still be very warm. Add chocolate chips, stirring as the chips melt. Pour into prepared pan.

Bake 20-25 minutes, or until toothpick inserted in center of pan comes out clean. Cool completely in pan.

Remove ice cream from container and cut into 3/4-in. thick slices. Place slices on top of brownie and use a spatula to help spread into an even layer. Place in freezer while preparing Whipped Icing Mix.

Prepare Whipped Icing Mix according to package instructions and spread on top of ice cream layer. Sprinkle with sprinkles and freeze until ready to serve. When ready to serve, remove from freezer and let stand 20 minutes at room temperature to soften slightly.