Using a zester, make a decorative design around the outside of oranges. Cut off about 1/2-inch from the tops of the oranges and remove a small slice from the bottom of the oranges, if oranges roll.
Hollow out most of the fruit and coarsely chop (about 1 cup). Place chopped fruit in a small mixing bowl and stir in orange peel, liqueur, and sugar. Let stand for 10 minutes or cover hollowed oranges and fruit separately, and chill in refrigerator overnight.
Prepare frosting mix according to package directions. Place frosting in a pastry bag with a 1/2-inch open round tip.
Fill oranges with fruit filling. Pipe on frosting. If desired, place in a 350 degrees F oven about 7 minutes or until lightly browned or brown with a torch