Grease 6 (6-oz.) ramekins or individual souffl dishes with 1 Tbsp. butter.
Microwave 1 cup butter and chocolate morsels in a microwave-safe bowl at HIGH 2 minutes or until chocolate is melted and mixture is smooth, whisking at 1-minute intervals.
Beat egg yolks and eggs at medium speed with an electric mixer 1 minute. Gradually add chocolate mixture, beating at low speed until well blended.
Sift together sugar and next 3 ingredients. Gradually whisk sugar mixture into chocolate mixture until well blended.
Whisk in orange liqueur and orange zest. Divide batter among prepared ramekins.
Place ramekins in a 15- x 10-inch jelly-roll pan.
Bake at 425 for 14 to 16 minutes or until a thermometer inserted into cakes registers 16
Remove from oven, and let stand 10 minutes. Run a knife around outer edge of each cake to loosen. Carefully invert cakes onto dessert plates.
Garnish, if desired.
Note: For testing purposes only, we used Ghirardelli 60% Cacao Bittersweet Chocolate Chips and Grand Marnier for orange liqueur.