Sift together flour, cocoa, and baking powder in a medium bowl; set aside.
Whisk together butter and next 5 ingredients in a large bowl. Add dry ingredients; combine well. Spoon batter into 8 lightly greased 6-ounce custard cups or ramekins. Sprinkle each with 2 tablespoons morsels. Cover and chill at least 2 hours. Bake, uncovered, at 350° for 22 minutes. (Edges will be set and centers will be soft.) Let stand 5 minutes before serving.
Note: To eliminate the risk of salmonella contamination, this recipe uses egg substitute instead of real eggs because the cakes aren't in the oven long enough for eggs to cook thoroughly.