1.  In a saucepan, mix 300 ml of champagne or sparkling wine with sugar and gelatin.  Leave for 2 minutes to gelatin soaking.  Put the saucepan on a small fire and cook for 2-3 minutes, stirring constantly, until gelatin is completely dissolved. 

2.  Remove from the heat and pour the remaining 150 ml of champagne or sparkling wine.  Mix well.  Transfuse liquid into molds for baking (pre-each can be laid out on the cherry cocktail or frozen) and put in the freezer for at least 1 hour. 

3.  To get jelly, dip the form in warm water and gently stroll along the wall with a knife.  Then gently turn over form.  Cut the jelly with a sharp knife into small squares.  Sprinkle with sugar.