Place water and Krusteaz Professional Fudge Brownie Mix in mixer bowl. Using a whisk, mix until smooth. If using Ready to Bake Brownie Batter, pour on to 1/2 sheet pan and spread with a spatula.
Scale batter into greased full sheet pan. Omit this step if using Ready to Bake Brownie Batter.
For convection oven, bake at 300°F 27-32 minutes; for standard oven, bake at 350°F 30-35 minutes. Cook Ready to Bake Brownie Batter according to instructions.
Cut into desired shape and plate.
Pipe icing on each brownie then stack with another brownie.