Cakes: Preheat oven to 350° F. With spray, coat 6 to 4 1/2-inch diameter nonstick individual springform pans; dust with flour; tap out excess.
In bowl, mix flour, baking powder and salt. In small cup, dissolve cocoa powder in food coloring.
In 1-quart bowl, mix buttermilk, vinegar, baking soda and vanilla extract.
In large bowl, with mixer at medium speed, beat butter and sugar until fluffy. Beat in eggs, then cocoa mixture. At low speed, alternately beat in flour mixture with buttermilk mixture until blended. Spread in pans.
Bake 22 minutes, until pick inserted into centers comes out clean. Let cool in pans on rack. Cut around top edges of cakes to loosen; remove sides of pans. Invert cakes on rack; remove pan bottoms. Re-invert cakes.
Frosting: In medium bowl, beat cream cheese, butter and vanilla extract until light and fluffy. At low speed, gradually beat in confectioners' sugar until no lumps remain and frosting is spreadable.
With serrated knife, split cakes horizontally. Fill and frost with cream cheese frosting. Refrigerate cakes until frosting is firm. Garnish with sour fruit candies, if desired. Cakes can be refrigerated in airtight container up to 2 days before serving.Servings: 6 cakes