Courtesy of KraftRecipes with my little tweaks
- PREPARE cake batter and bake as directed on package for 13x9-inch pan. Cool cake in pan 15 min. Pierce cake with large fork at 1/2-inch intervals.
- ADD boiling water to gelatin mix in small bowl; stir 2 min. until completely dissolved. Stir in cold water; pour over cake. Refrigerate 3 hours.
- WHIP the cream together with the icing sugar and vanilla extract. Frost the cake.
- CHOP the grapes into quarters and put into a sandwich bag. Pour some purple glimmer sugar in the bag. Shake the bag up so the sugar sticks to the grapes. Scatter the covered grapes all over the frosted cake.