Corn and Black Bean Tortilla Cakes

In a bowl, toss together beans, corn, and onion. In another bowl, toss together cheeses. Put 3 tortillas in one layer on a large heavy baking sheet. Sprinkle each tortilla with about 1/3 cup bean mixture and about 1/3 cup cheese mixture and top with a second tortilla; Make 2 more layers on each tortilla in same manner with remaining bean mixture, cheeses, and tortillas, gently pressing each layer down and ending with a fourth tortilla on top of each cake. Tortilla cakes may be prepared up to this point 6 hours ahead and chilled, wrapped well in plastic wrap. Preheat oven to 450 °F. In a small bowl, stir together oil and cayenne and lightly brush mixture over top of each cake. Bake cakes in middle of oven until golden, about 12 to 15 minutes. Cut cakes into wedges and serve immediately.