Peel the peach. Cut half of the flesh into small pieces and keep the remainder for decoration. Put the pieces of peach, peach liqueur and Prosecco into the blender. Blend for 15 seconds on speed 1.
Pour the cocktail through a sieve into a champagne glass.
Very finely chop the remaining peach and arrange the pieces on the cocktail.
Tips: If you cannot buy peach liqueur you can use peach schnapps instead.