To make rhubarb compote, put 2 cups chopped rhubarb stalks in a medium pot with 3 tablespoon water and 2 tablespoon maple syrup. Stir and bring to a boil. Reduce heat and simmer for 15-20 minutes until tender. Purée in a blender and store in the refrigerator.
Spoon 3 tablespoons of rhubarb compote into each of 2 champagne flutes or cocktail glasses. Slowly fill glasses with Prosecco. It may bubble up, so add a little at a time to prevent it from overflowing.