Preparation time: 5 to 7 minutes
Baking time: 27 to 29 minutes
Assembly time: 15 minutes
Cake:
Solid vegetable shortening for greasing the pans
Flour for dusting the pans
1 package (18.25 ounces) plain white cake mix
1 1/3 cups water
2 tablespoons vegetable oil, such as canola, corn, safflower, soybean, or sunflower
3 large eggs
Coconut frosting:
2 cups sugar
2 cups (16 ounces) sour cream
1 package (12 ounces, 3 1/2 cups) frozen unsweetened grated coconut, thawed
1. Place a rack in the center of the oven and preheat the oven to 350°F. Generously grease two 9-inch round cake pans with solid vegetable shortening, then dust with flour. Shake out the excess flour. Set the pans aside.
2. Place the cake mix, water, oil, and eggs in a large mixing bowl. Blend with an electric mixer on low speed for 1 minute. Stop the machine and scrape down the sides of the bowl with a rubber spatula. Increase the mixer speed to medium and beat 2 minutes more, scraping the sides down again if needed. The batter should look well blended. Divide the batter between the prepared pans, smoothing it out with the rubber spatula. Place the pans in the oven side by side.
3. Bake the cakes until they are golden brown and spring back when lightly pressed with your finger, 27 to 29 minutes.
4. Meanwhile, prepare the frosting. Combine the sugar, sour cream, and thawed coconut in a medium bowl. Let the mixture rest in the refrigerator until the sugar dissolves, 1 hour, stirring occasionally.
5. Remove the pans from the oven and place them on wire racks to cool for 10 minutes. Run a dinner knife around the edge of each layer and invert each onto a rack, then invert them again onto another rack so that the cakes are right side up. Allow them to cool completely, 30 minutes more.
6. When the sugar has dissolved in the frosting, begin to assemble the cake. Carefully slice the cake layers in half horizontally, using a large, sharp serrated bread knife or a long piece of unflavored dental floss. You will have four layers. Place the bottom half of a cake layer on a serving platter, cut side up. Spread with some of the coconut frosting. Top the bottom half with the matching top of the layer, cut side down. Spread with frosting. Next, add the bottom half of the second layer, cut side up, and spread with frosting. Top the bottom half with the matching top of the layer, cut side down. Spread the top and sides of the entire cake with all of the remaining coconut frosting, using clean, smooth strokes. The frosting should be nice and thick and not run off the sides.
7. Chill the cake, uncovered, until the frosting is firm, 1 hour.
Note: Store this cake covered with waxed paper taped down along the underside of the platter to keep it snug. It will keep in the refrigerator for up to 1 week.
