Of course you could serve this buttery sponge cake plain (or splashed with a little sweetened espresso or coffee liqueur) and topped with strawberries and whipped cream. But the brown rice flour adds a delicate caramel flavor to the cake, so why not run with it? This riff on the traditional Latin American tres leches—sponge cake drenched in a combo of heavy cream, sweetened condensed milk, and evaporated milk—is less sweet and less drenched than the authentic version, but a terrific variation nonetheless. The warm or cooled cake is poked with a chopstick or the not-too-thick handle of a wooden spoon and then soaked with a sauce of dulce de leche and evaporated milk. The third “milk” is whipped cream on top. More sauce is passed separately at table. What could be more delicious?
Serves 10 to 12
For the cake
6 tablespoons (85 grams) clarified butter or ghee
¾ cup (100 grams) brown rice flour, preferably superfine
⅔ cup (130 grams) sugar
4 large eggs
⅛ teaspoon salt
For the sauce
1 can (12 ounces) evaporated milk
1 generous cup (350 grams) purchased dulce de leche or cajeta
⅛ teaspoon salt
Whipped cream, unsweetened or very lightly sweetened
8-by-2-inch round cake pan
Stand mixer with whisk attachment
Sifter or medium-mesh strainer
Position a rack in the lower third of the oven and preheat the oven to 350°. Line the bottom of the pan with parchment paper, but do not grease the sides of the pan. Put the clarified butter in a small pot or microwavable container ready to reheat when needed, and have a 4- to 5-cup bowl ready to pour it into as well—the bowl must be big enough to allow you to fold some batter into the butter later.
Whisk the flour and 2 tablespoons of the sugar together thoroughly in a medium bowl. Combine the remaining sugar, eggs, and salt in the bowl of the stand mixer and beat with the whisk attachment on high speed for at least 5 minutes. The mixture should be light colored and tripled in volume, and you should see well-defined tracks as the whisk spins; when the whisk is lifted, the mixture should fall in a thick, fluffy rope that dissolves slowly on the surface of the batter. Just before the eggs are ready, heat the clarified butter until very hot and pour it into the reserved bowl.
Remove the bowl from the mixer. Sift one-third of the flour over the eggs. Fold with a large rubber spatula until the flour is almost blended into the batter. Repeat with half of the remaining flour. Repeat with the rest of the flour. Scrape about a quarter of the batter into the hot butter. Fold until the butter is completely blended into the batter. Scrape the buttery batter over the remaining batter and fold just until blended. Scrape the batter into the pan.
Bake for 30 to 35 minutes, until the cake is golden brown on top. It will have puffed up and then settled level, but it won’t have pulled away from the sides of the pan, and a toothpick inserted in the center will come out clean and dry. Set the pan on a rack. While the cake is still hot, run a small spatula around the inside of the pan, pressing against the sides of the pan to avoid tearing the cake.
At your convenience (the cake can be warm or completely cool), invert the pan to remove the cake and peel off the parchment liner. Turn the cake right side up. (The cake should be completely cool before storing.) The cake may be wrapped airtight and stored at room temperature for 2 days, or frozen for up to 3 months.
To assemble the cake, an hour (or up to several hours) before serving, set the cake (cooled or warm) on a rimmed serving platter and poke holes 1 inch apart all over it with a chopstick or a thin wooden spoon handle. Make the sauce by stirring the evaporated milk, dulce de leche, and salt together until smooth. Spoon 1½ to 2 cups of the sauce over the cake, a little at a time, allowing it to be absorbed. Use the greater quantity if you want a more soaked cake, or let some of the delicious cake remain dry. Either way, pass the extra sauce at the table. Make sure the cake is completely cool before topping it with swirls of unsweetened or very lightly sweetened whipped cream, leaving the sides bare. Refrigerate the cake in a covered container or under a cake dome. Leftover cake keeps in the refrigerator for a few days.