Paradise Cake

Ingredients

• 1 cup (125 g) cake flour
• ⅔ cup (125 g) potato starch
• 2 teaspoons baking powder
• ¼ teaspoon fine sea salt
• Finely grated zest of 1 lemon or 1 orange (optional)
• 1¼ cups (250 g) granulated sugar
• 18 tablespoons (9 oz/254 g) unsalted butter, cut into chunks and softened to room temperature
• 5 large eggs, at room temperature, lightly beaten
• 1¼ cups (300 ml) heavy cream, for the optional filling or accompaniment
• ½ cup (120 ml) sweetened condensed milk, for the optional cream
• 1¾ teaspoons pure vanilla extract, for the optional cream
• Confectioners’ sugar, for topping

Instructions

1. Center a rack in the oven and preheat to 350°F (175°C). Butter and flour a 9-inch round cake pan with sides at least 2 inches high, or use a 9-inch springform pan. Tap out the excess flour and line the bottom with parchment paper.
2. Whisk the cake flour, potato starch, baking powder, and salt together in a medium bowl until evenly blended.
3. In a stand mixer fitted with the paddle attachment, beat the softened butter, sugar, and optional citrus zest on medium speed until very pale, fluffy, and creamy, about 4 minutes. Scrape the bowl and beater frequently.
4. With the mixer on medium-low, add the lightly beaten eggs gradually, a few tablespoons at a time, allowing each addition to blend before adding more. If the mixture looks curdled, add a spoonful of the dry ingredients and continue mixing.
5. Add the dry ingredients in three additions, mixing on low only until each addition disappears. Finish folding gently by hand, making sure no flour remains at the bottom of the bowl. Scrape the batter into the prepared pan and smooth the top.
6. Bake for 45 to 50 minutes, until the cake is tall and golden, springs back when lightly pressed, and a tester inserted in the center comes out clean. Cool in the pan for 10 minutes, then unmold onto a rack and cool completely.
7. For the optional sweetened cream, whip the heavy cream, condensed milk, and vanilla to soft peaks. Serve the cake at room temperature with a generous dusting of confectioners’ sugar and the cold cream alongside, or split the cooled cake horizontally and use the cream as a filling.