For the cake:
¾ cup cake flour
¼ tsp. baking powder
Pinch of salt
2 large eggs, separated, plus 1 large egg yolk, at room temperature
½ cup sugar
2 tbsp. cold water
½ tsp. vanilla extract
For the custard:
½ cup plus 2 tablespoons whole milk
¼ cup sugar
½ vanilla bean, split lengthwise
1½ tbsp. cornstarch
¼ cup canned Thai coconut milk
2 large egg yolks
½ cup dried shredded coconut (I used unsweetened)
For the fruit filling:
½ small-medium pineapple, peeled, cored and diced small
1-2 kiwifruit, peeled and diced small
1¼ cups strawberries, hulled and diced small
½ medium mango, peeled, pitted and diced small
3 tbsp. sugar
Juice of ½ lime
¼ cup dark rum (optional)
To make the sponge cake, preheat the oven to 350˚ F. Lightly butter the sides of a 9 x 5-inch loaf pan. Line the bottom with parchment paper. In a small bowl, combine the flour, baking powder and salt. Whisk to blend and set aside. In the bowl of a stand mixer fitted with the whisk attachment, beat the egg whites on high speed until they form stiff peaks. Transfer to another bowl and wipe out the mixer bowl. Fit the mixer with the paddle attachment. In the now empty mixer bowl, beat the egg yolks and water on medium-high speed for 1 minute. Mix in the sugar and vanilla. Increase the speed to high and continue to beat until the mixture forms a ribbon when the paddle is lifted, about 5 minutes.
Gradually add the flour mixture to the bowl with the beaten egg yolks, gently folding with a spatula. Once the flour is incorporated and no streaks remain, fold in one third of the egg whites to lighten the batter. Gently fold in the remaining egg whites.
Pour the batter into the prepared pan. Bake until the cake is lightly browned and springs back when gently pressed, about 35-40 minutes. Transfer to a wire rack and let cool in the pan. Run a knife around the edges to loosen the cake from the pan. Keep the cake well wrapped until you are ready to assemble the trifles.
To make the custard, combine the milk and sugar in a small saucepan over medium heat. Scrape the seeds from the vanilla bean and add them to the saucepan. Then drop in the vanilla pod as well. In a small bowl, whisk together the cornstarch and coconut milk until completely smooth. In another bowl, whisk the egg yolks briefly. When the milk-sugar mixture is warm, stir the cornstarch mixture briefly to recombine and then stir it into the milk mixture. Cook, stirring constantly, until the mixture thickens. Very slowly add about one third of the hot milk mixture to the bowl with the egg yolks, whisking constantly. Then transfer the egg yolk mixture to the pan with the thickened milk mixture. Cook, stirring constantly and scraping the bottom of the pan, just until the mixture begins to boil. Immediately remove from the heat and pour the mixture through a fine mesh sieve into a bowl or storage container. Stir in the coconut, cover, and refrigerate until chilled.
To make the fruit filling, add the pineapple and kiwi (if using) to a nonreactive skillet. Gently cook over medium heat just until the fruit is heated through, about 3 minutes. Transfer to a medium bowl and let cool completely. Stir in the strawberries, mango, sugar, lime juice and rum. Toss gently to combine.
When you are ready to assemble the trifles, cut the cake into small cubes using a serrated knife. To assemble the trifles, spread a thin layer of the custard over the bottom of each trifle dish. Top with a single layer of cake cubes. Spoon some of the fruit filling over the top of the cake cubes. Layer once more with cake cubes and the fruit mixture, and top with the remaining custard. Garnish with additional toasted coconut, if desired. Serve within 6 hours of assembly.
*Note: The amount of sponge cake in this recipe makes twice as much as you need for 4 mini trifles. I freeze the leftover cake for another use, but if you don’t want the extra you could divide it in half even further and bake in ramekins or muffin tins. If you would like to make a full size trifle, double the recipe and layer in a full size trifle dish. A smaller size dice is preferred for the fruit in individual trifles, but larger chunks are better suited for making a full size trifle.