1

Preheat the oven to 350°F. Spray two 8-inch round cake pans with nonstick spray. Line with wax-paper rounds; spray with nonstick spray.

2

Whisk together the cake flour, cinnamon, baking powder, baking soda, and salt in a medium bowl; set aside. With an electric mixer on high speed, beat the eggs and egg whites in a large bowl until thickened, about 2 minutes. Gradually add the granulated sugar, beating until light and fluffy, about 3 minutes. Reduce the speed to low. Beat in the apple butter and oil just until blended. Add the flour mixture and beat just until blended. Stir in the pineapple, carrots, and raisins.

3

Divide the batter evenly between the pans. Bake until a toothpick inserted into the center comes out clean, about 35 minutes. Let cool in the pans on racks 10 minutes. Invert the layers onto racks and remove the wax paper; let cool completely.

4

To make the frosting, with an electric mixer on high speed, beat the frosting ingredients in a medium bowl until smooth, about 1 minute.

5

Place 1 cake layer, rounded side down, on a serving plate. With a narrow metal spatula, spread 1⁄3 cup of the frosting over the layer. Top with the remaining layer, rounded side up. Spread the remaining frosting over the top and side of the cake. Sprinkle the walnuts on top of the cake. Yields 1⁄16 of cake per serving.