For centers, in a saucepan, melt Ghirardelli(R) Peppermint Bark Baking Bar and cream over low heat. Remove from heat. Whisk gently to blend. Freeze for 1 hour or until firm. Form into 6 balls; refrigerate until needed.
For cake, preheat oven to 400 degrees F. Spray six 6-ounce ramekins or custard cups with nonstick cooking spray; set aside. In a double boiler, melt Ghirardelli(R) 60% Cacao Bittersweet Chocolate Baking Chips and butter over low heat. Remove from heat. Whisk gently to blend.
In a large bowl, beat eggs, egg yolks, sugar, and peppermint extract with an electric mixer on high speed for 5 minutes or until thick and light. Fold melted chocolate mixture and flour into egg mixture just until combined. Spoon cake batter into prepared ramekins. Gently press a chocolate ball into center of cake batter in each ramekin.
Bake for 15 minutes or until cake is firm to the touch. Let ramekins stand on a wire rack for 5 minutes. Run a small, sharp knife around inside of each ramekin. One at a time, place a small plate on top of each ramekin, invert, and remove ramekin. If desired, top each cake with a small scoop of vanilla ice cream and finely chopped Ghirardelli(R) Peppermint Bark.