This dessert may take some time to make but it's guaranteed to impress your guests. The teacups are made with melted chocolate and filled with a fluffy chocolate-mint mousse.
Using scissors, on each cup cut 4 slits, evenly spaced, from top to bottom (see photo 1, below left). Tape slits closed with masking tape on outside of cups (photo 2).
Place chopped chocolate in medium-size microwave-safe bowl. Microwave on high power for 1-1/2 minutes. Stir; microwave another 30 to 60 seconds or until almost melted. Stir to melt completely. Let stand about 1 minute or until temperature is about 115 degrees F on instant-read thermometer.
Place 2 heaping tablespoons melted chocolate in one cup. Swirl to coat inside of cup; use pastry brush to evenly coat (photo 3). Place cup, open side up, on waxed paper-lined baking sheet. Working quickly, repeat with remaining 7 cups.
After 5 minutes, rebrush chocolate evenly in cups. Place on waxed paper, open side down. Refrigerate while continuing.
Place remaining melted chocolate in small resealable plastic food-storage bag. Snip very small hole in one corner. On another waxed paper-lined baking sheet, pipe 8 handles in shape of letter D, about 1 inch high. For stirrers, on waxed paper, pipe 8 lines about 1-1/2 inches long and about 1/4 inch thick. (Make extra handles and stirrers to allow for breakage.) Refrigerate 15 minutes or until chocolate is firm. Reserve chocolate-filled plastic bag at room temperature.
Remove masking tape from cup. Carefully peel cup away from chocolate (photo 4). Gently pop bottom of chocolate cup from the paper cup. Repeat process.
Microwave reserved chocolate in plastic bag at 30 second intervals or until just melted. Pipe a 1-inch-long vertical line on side of cup. Using toothpick, gently lift a handle off waxed paper and place on melted chocolate to attach to cup. Repeat with remaining cups. Refrigerate 15 minutes until chocolate is firm, or up to a few days. (Reserve chocolate in plastic bag at room temperature for any repairs.)
In small saucepan, heat 3/4 cup of the heavy cream until small bubbles appear around edge of pan. Place chopped chocolate in large bowl. Pour hot cream over; let stand 1 minute. Stir until chocolate is melted. Stir in liqueur. Let cool 10 to 15 minutes or until mixture registers 80 degrees F on instant-read thermometer.
In large bowl, beat remaining heavy cream on medium-high speed until stiff peaks form. With whisk, stir about one-quarter of whipped cream into chocolate mixture to lighten. Gently fold in remaining whipped cream. Cover; refrigerate at least 2 hours or overnight.
Spoon mousse into large pastry bag fitted with large star tip; pipe into cups. (Cups can be filled 3 hours ahead; refrigerate.) Garnish with stirrers, and candy, if desired. Makes 8 cups.