Chop the couverture and melt in a hot water bath. Warm the cream and champagne. Remove the pot from the heat, add coconut oil and butter and melt in it. Add couverture, stir in and chill for about 2 hours.
Then whisk with the whisks of the hand mixer to a creamy mixture. Pour the cream into a piping bag with a small perforated spout and squirt into the sleeves. Sprinkle with sugar. Results in about 30 pieces