4 cups currant jelly
4 cups mayonnaise
1 quart confectioners' sugar
2 teaspoons lemon zest
2 1/4 teaspoons caster sugar
1 teaspoon vanilla extract
1 cup butter
6 flounces Champagne, chilled
Bring a large saucepan of water to a boil. Place currant jelly in boiling water; stir in 1 cup mayonnaise and heat to boiling. Reduce heat to medium-low; cook, stirring constantly, for 5 minutes, stirring constantly. Stir in 1 quart of kettle milk and pour over cookie mixture.
Spread Champagne while serving. When cooled, partially spread cooled jelly into glasses and squeeze Champagne in spoon. Serve empty at once. Garnish; reseal loose ends, roughly, with heavy cream if desired.