1. Preheat oven to 425°. Grease 6 (6-oz.) ramekins or individual soufflé dishes with 1 Tbsp. butter.
2. 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.
3. 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.
4. 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.
5. Bake at 425° for 14 to 16 minutes or until a thermometer inserted into cakes registers 165°. 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.