Remove waxed paper. Cut each layer in half to make a total of 4 half-moons. Measuring 2 inches along cut edge of each cake from end, cut out notch, 2 inches deep. (Reserve cake notches for snacks.) On a serving platter, place 2 half-moons or wings, rounded sides touching in middle, and notches opposite each other on outside edges. The shape should resemble a butterfly. Spread top of wings with marmalade. Top with remaining 2 wings, lining up notches. Spread top and sides of cake with frosting.