I was looking for a good end of summer desert to make and since we were having friends over for pork bbq I wanted something big enough to feed all of us. I had a couple of rum cakes in mind, but I decided to flip through my book Sky High -- Irresistible Triple Layer Cakes since I had not used it before even though I have owned it for several months now. The Pina Colada Cake struck me as perfect. Pineapple, coconut, and rum all in triple layer cake form.
There were a lot of steps to making this cake, but it wasn't difficult at all. The cakes themselves are a simple brown sugar cake recipe, although with one of the strangest mixing methods I have seen. The filling is a pineapple jam that you make using sugar, lime juice, canned pineapple and vanilla bean. It takes a while to cook down to the right consistency, but the process is easy enough. The original recipe called for a cooked buttercream frosting using coconut milk and coconut extract but I didn't want to deal with a finicky frosting, so I made a regular buttercream using butter, powdered sugar, a couple tablespoons of coconut milk, and a tsp of coconut extract. The trick to getting a butter/powdered sugar buttercream frosting silky and smooth is to sift the powdered sugar and add it to the butter slowly -- a tablespoon at a time. It's time consuming, but worth it.
Brown Sugar Cake:
3 3/4 cups cake flour
1 3/4 tsps baking soda
1 tsp baking powder
1/2 tsp salt
2 1/4 cups light brown sugar
2 sticks unsalted butter at room temp
1 3/4 cup buttermilk
5 eggs
2 tsps vanilla extract
Preheat the oven to 350. Spray 3 9-inch round cake pans with baking spray (or butter and sprinkle with flour).
Put the flour, baking soda, baking powder and salt in the bowl of a large mixer. Mix on low and then add the brown sugar, butter, and 1 1/2 cups of the buttermilk. Mix on low until everything is incorporated, then increase the speed to medium and mix until light and fluffy -- about 2 or 3 minutes.
Whisk the eggs with the remaining 1/4 cup buttermilk and the vanilla and add to the flour butter mixture in three additions, allowing the eggs to fully incorporate before adding the next addition. Divide the batter between the three pans.
Bake 25-28 minutes or until a cake tester inserted in the middle comes out clean. Cool for 10 minutes in the pans and then turn our to cool completely. You may have to trim the tops of the cakes to level them off some.
Pineapple Filling
20 oz crushed pineapple in juice (no sugar added)
1 cup sugar
1/4 cup freshly squeezed lime juice
1 one-inch vanilla bean, split in half
Combine the crushed pineapple, sugar, and lime juice in a large nonreactive skillet. With the top of a small knife scrape the vanilla seeds from the bean and add them and the bean itself to the pot. Warm over medium-low heat stirring to dissolve the sugar.
Raise the heat to medium and simmer, stirring occasionally to prevent scorching, until the juices have almost completely evaporated and the pineapple has a jam-like consistency Remove from heat and discard the vanilla pod. Let the filling cool completely before using.
Coconut Buttercream
2 sticks butter at room temp
3 1/2 -4 cups powdered sugar, sifted
2 tablespoons coconut milk (or heavy cream if you don't want to use coconut milk)
1/2 tsp coconut extract (you might use more extract if you don't use coconut milk -- basically just add 1/2 tsp and add more if you want a more assertive coconut flavor)
Put the butter in a large mixing bowl and beat on medium speed until the butter is smooth. Add the powdered sugar one spoonful at a time and let each spoonful fully incorporate before adding the next. It will take a long while to get through this process, but the resulting texture is worth it. Once all the sugar is mixed in add the coconut milk and coconut extract and mix completely. If the frosting looks runny at all add more powdered sugar slowly until you get a soft, silky frosting.
Assembly:
2/3 cup rum (dark, amber, light -- whatever you like best)
coconut flakes
To assemble the cake place one layer flat side up on a cake stand or serving platter. Brush the cake with 3 generous tablespoons of rum. Spread half the pineapple filling over the layer, leaving a 1/4 inch margin around the edge. Add the second layer, sprinkle with more rum and then the remaining pineapple jam. Top with the third layer, flat side up and sprinkle with the remaining rum. Frost the top and the sides of the cake with the coconut buttercream. Decorate the cake by pressing coconut flakes to the side. You can also toast the coconut for a more dramatic finish -- just spread the coconut on a baking sheet and put in a 350 degree oven. Watch it carefully because the coconut burns quickly. When some of it is brown it's ready.