Preheat oven to 400 degrees.
For filling, in a heavy, small saucepan combine the 3/4 cup chocolate pieces and the whipping cream.
Cook and stir over low heat until chocolate is melted.
Remove pan from heat.
Cool, stirring occasionally.
Chill in refrigerator for 30 to 45 minutes or until firm.
Meanwhile, in a heavy medium saucepan cook and stir the 1 cup chocolate pieces and the butter over low heatuntil melted.
Remove from heat; cool.
Form chilled filling into 6 equal-size balls; set aside.
Lightly grease and flour 6 3/4 souffle dishes or 6-ounce custard cups.
Place dishes or cups on a 15 x 10 x 1 inch baking pan; set aside.
In large bowl beat whole eggs, egg yolks, granulated sugar and vanilla with an electric mixer on high speed 5 minutes or until lemon colored.
Beat in chocolate-butter mixture on medium speed.
Sift flour and cocoa powder over mixture; beat on low speed just until combined.
Fill prepared dishes with about 1/3 cup batter.
Place 1 ball of filling into each dish.
Spoon remaining batter into dishes.
To make ahead, after filling dishes, cover and chill in refrigerator until ready to bake or up to 4 hours.
Let stand at room temperature 30 minutes before baking.
Bake about 13 minutes or until cakes feel firm at edges.
Cool in dishes 2 to 3 minutes.
Using a knife, loosen cakes from sides of dishes.
Invert onto dessert plates.
If desired, dust with powdered sugar; serve with Chocolate Whipped Cream or ice cream.