Wash the grapes thoroughly and remove each grape from the stem.

Using a toothpick, poke several holes in each grape.

Place the pierced grapes in a large bowl and pour the prosecco or champagne over them. Cover the bowl and refrigerate for a minimum of 8 hours, preferably overnight.

After marination, drain the prosecco from the grapes.

While the grapes are still wet, toss them in cane sugar.

Spread the sugar-coated grapes in a single layer on a baking sheet lined with parchment paper and freeze.

Serve chilled or frozen.