Beat first 4 ingredients at low speed with an electric mixer 2 minutes; then beat at medium speed 3 minutes or until blended. Stir in chocolate morsels. Spoon batter evenly into 16 to 18 paper-lined muffin pans.
Bake at 350° for 15 minutes.
Remove from oven. Make a small indention in center of each hot cupcake. Spoon 2 teaspoons Chocolate Filling into each center. Remove from pans, and let cool completely on a wire rack.
Spread cupcakes with Buttercream Frosting.