With serrated knife, cut off domed top of each cake layer to level. Carefully brush off crumbs. Place 1 cake layer, cut side up, on serving plate; spread with 1/4 cup jam. Spread 3/4 cup frosting over jam. Repeat with second cake layer, cut side up, 1/4 cup jam and 3/4 cup frosting. Top with remaining cake layer, cut side down. Using large spatula, carefully spread thin layer of frosting over sides of cake, then over top, to seal in crumbs. Refrigerate 30 minutes. Apply second thicker layer of frosting to sides and top of cake, spreading until smooth.