Adapted from Steph’s Sour Lime Pina Colada From the Great British Bake Off
Makes one cake 8 inches in diameter with 4 layers.
Sponges
375 g all purpose flour
1 tablespoon plus 1 ½ teaspoons baking powder
¾ teaspoons salt
375 g butter at room temperature
375 g granulated sugar
6 eggs at room temperature
2 tablespoons lactose free whole milk
For the coconut sponge
60 g desiccated coconut, pulsed in a food processor until finely chopped
2 tablespoons coconut cream
For the lime sponge
Zest of 3 limes, finely grated
1 ½ tablespoons lime juice, freshly squeezed
⅛ teaspoon green food coloring paste
Make the sponges
Preheat the oven to 350° F.
Line the bottom of 2 round cake tins that are 8 inches in diameter with parchment circles. Butter and flour the sides of the tins and set aside.
Sift the flour, baking powder, and salt together and set aside. Using a stand mixer, beat the butter and sugar until light and fluffy. Add the eggs one at a time, beating until combined after each addition. Add the flour and the milk. Beat until all the flour is incoporated.
Divide the mixture evenly between two bowls. To one bowl stir in the coconut and coconut cream. To the second blow stir in the lime zest, lime juice and green food coloring.
Pour the coconut batter into one tin and the lime batter into the second tin. Bake in the preheated oven for 30 to 35 minutes or until a tester inserted into the center of the cake comes out clean. Cool for 5 minutes in the tins then remove from tins and cool completely on a rack.
Pineapple and Lime Curd
7 tablespoons pineapple juice from a can of pineapple packed in 100% pineapple juice
Zest of 4 limes
6 tablespoons freshly squeezed lime juice
50 g granulated sugar
3 eggs
3 egg yolks
150 g butter at room temperature
Heat a pan of water to a simmer. Choose a bowl that fits over the pan of water but doesn’t touch the simmering water. In the bowl off the heat rub the lime zest into the sugar until moist and very fragrant. Add the pineapple juice, lime juice, eggs and egg yolks. Whisk to combine. Whisk over the simmering water until the mixture thickens and reaches 180° F. Remove from heat and pass through a strainer into the bowl of an electric mixer. Let cool to 140° F.
Using the paddle attachment, mix the cooled cream on medium speed. Add small pieces of the butter a few at a time. Beat until the pieces disappear before adding more butter. Once all the butter is incorporated, continue mixing for another minute.
Pack in an airtight container and refrigerate until ready to use.
Italian Meringue Buttercream
300 g granulated sugar
¼ cup water
4 egg whites at room temperature
1 pinch salt
1 pinch cream of tartar
400 g butter at room temperature
Yellow and green food coloring paste
In a small saucepan, heat the sugar and water until the sugar melts. Brush the side of the pan with water to dissolve any sugar clinging to the sides. Clip a candy thermometer to the side of the pan. Allow the mixture to boil undisturbed until reaching 240° F.
While the sugar mixture boils, beat the egg whites in the bowl of an electric mixer fitted with a whisk attachment. Once the egg whites are foamy add the salt and cream of tartar. Continue beating at high speed until soft peaks form.
Once the sugar mixture reaches 240° F pour the mixture into the egg whites while beating at a low speed. Pour the mixture slowly between the whisk and the side of the bowl. Once all the syrup is incorporated, increase the speed to high and continue beating until the bottom of the bowl is cool.
Once the meringue is cooled, beat in the butter a few small pieces at a time. Add more small pieces only after the previous ones disappear.
Divide the buttercream into 3 bowls. Place half the butter cream in one bowl. This will be the white buttercream. Divide the remaining buttercream equally between the other 2 bowls. Add yellow food coloring to one of the bowls and green food coloring to the other bowl. Stir until a uniform color is achieved in each bowl.
Rum buttercream
112 g butter at room temperature
200 g powdered sugar, sifted
1 ½ tablespoons rum
Beat the butter in the bowl of an electric mixer fitted with a paddle attachment until creamy. Slowly add the powdered sugar and rum on low speed. Once incorporated, increase the speed to high for a minute.
Assemble the cake
Cut the coconut layer in half to create 2 layers. Cut the lime layer in half to create 2 layers. Place the top coconut layer cut side up on a cake plate. Brush with pineapple syrup. Frost the top with ⅓ of the rum buttercream. Add a generous layer of the lime and pineapple curd leaving a little room at the edge.
Place the top lime layer on top of the coconut layer cut side up. Brush with pineapple syrup. Frost the top with ⅓ of the rum buttercream. Add a generous layer of lime and pineapple curd leaving a little room at the edge.
Add the remaining coconut layer cut side down. Poke the layer with a toothpick so that the syrup absorbs better. Brush with pineapple syrup. Frost with the remaining rum buttercream. Add a generous layer of the lime and pineapple curd leaving a little room at the edge.
Place the remaining lime layer on top cut side down. Poke with a toothpick and brush with the pineapple syrup.
Using the white Italian meringue buttercream crumb coat the top and sides of the cake with a thin layer. Refrigerate for 15 minutes.
Once chilled, pipe the green Italian meringue buttercream around the bottom of the cake. Pipe the yellow Italian meringue buttercream around the top. Using a bench scraper or spatula smooth the green and yellow buttercream around the side of the cake.
Paint the insides of a piping bag fitted with a star tip with a thin line of green food coloring paste. Leaving some space paint a thin line of yellow food coloring paste. Fill the bag with the remaining white Italian meringue buttercream. Pipe rosettes on top of the cake. If desired, top with a few maraschino cherries.
Store refrigerated for up to a week.
