Make the Chocolate Cups: Partially melt 1-1/4 cups chocolate over a double boiler set over hot, not boiling, water. When chocolate is about half melted, remove from heat, stirring continually until all the chocolate has melted. Let cool to about 95°F. Dip a small brush into the chocolate and paint the inside of the cupcake liners. Invert and place the chocolate cupcake liners on a plate and place in the freezer for about 2 minutes or until the chocolate hardens. Remove and add another coat of chocolate to the insides (particularly the sides) of the cupcake liners. Return the chocolate cups to the freezer for about 5 minutes. Carefully peel off paper; set cups aside in a cool area (or return to the freezer).
Make the Champagne Ice Cream: Combine 1/2 cup Champagne with sugar in a small saucepan and bring to a boil over medium-high heat. Continue to boil, without stirring, until a candy thermometer inserted into the syrup registers 236°F.
Meanwhile, beat the egg yolks in a large bowl on high speed until light and lemon colored. When the syrup has reached 236°F, add the syrup to the egg yolks in a thin, steady stream, beating constantly until the mixture is thick and creamy, about 7-10 minutes. Gradually blend in remaining 1/4 cup Champagne. Chill until mixture is thick but not stiff, about 30 minutes.
Whip cream in a chilled bowl until stiff. Fold into the Champagne mixture. Cover the bowl and freeze overnight.
Make the Chocolate sauce: Combine 6 tablespoon Champagne, 1/2 cup chopped semisweet chocolate, and 1 tablespoon sugar in a small saucepan. Stir over low heat until the chocolate is melted and sugar is dissolved. Whisk in the butter. Lower heat to low to keep warm.
To serve, spoon about 1/2 cup of the frozen Champagne ice cream into a bowl and microwave for 30 seconds or until melted. Spoon about 1-1/2 tablespoons melted ice cream onto the center of a dessert plate. Place the chocolate cup on top of the cream and top with a scoop of Champagne ice cream. Drizzle chocolate sauce over the top and serve immediately.
This is a very delicate and wonderfuly delicous dessert to serve for any special occasion.