Makes: 1 cake
You’ll be surprised by just how light and airy this cake is. You can coat it with chocolate glaze, as we’ve done here, but it is even better straight from the oven, without being soaked in syrup or glazed.
For the vanilla cake batter
- 1 stick (4 oz./120 g) unsalted butter + extra for the pan
- 1½ cups (10½ oz./300 g) sugar
- Scant 1 tsp (2 g) vanilla powder
- Generous ¾ tsp (about 4 pinches) fleur de sel sea salt
- 2 large eggs (½ cup/120 g)
- Scant 1¾ cups (7 oz./210 g) all-purpose flour
- 1½ tsp (6 g) baking powder
- Generous ¾ cup (200 ml) whipping cream
For the chocolate cake batter
- ½ cup (2 oz./60 g) unsweetened cocoa powder, sifted
- 1 tsp softened butter to pipe on the batters
For the rum syrup
- 1 cup (250 ml) water
- 1 tbsp (15 ml) dark rum
- 2⅓ cups (1 lb./450 g) superfine sugar
For the chocolate glaze
- 1 lb. 10oz. (750 g) pâte à glaçer brune (brown glazing paste), chopped
- 9 oz. (250 g) dark chocolate, 70% cacao, chopped
- ½ cup (125 g) grape-seed oil
For the vanilla cake batter and the chocolate cake batter
1Grease a large loaf pan with butter.
2In the bowl of a stand mixer fitted with the whisk, beat the butter, sugar, vanilla powder, and salt until light and creamy.
3Add the eggs and whisk in. Scrape down the sides of the bowl using a dough scraper, sift in the flour and baking powder, and incorporate on low speed.
4Immediately pour in the cream and whisk again until the batter is smooth.
5Spoon slightly less than half the batter into a separate bowl. Stir in the cocoa powder to make the chocolate batter.
6Preheat the oven to 300°F (150°C/Gas Mark 2).
7Transfer the vanilla and chocolate cake batters to two separate pastry bags, each fitted with large plain tips. Pipe the batters alternately into the loaf pan.
8Spoon the softened butter into a paper piping cone, snip off the tip, and pipe a line of butter lengthwise down the center of the batter.
9Bake for about 1½ hours, watching it carefully: the cake is ready when the tip of a knife pushed into the center comes out clean.
For the rum syrup
1Heat the water, rum, and sugar in a saucepan, stirring until the sugar dissolves. Bring to a boil and set aside.
2Remove the cake from the oven and immediately turn it out onto a wire rack. Brush the syrup over it.
3Cover the cake with plastic wrap while it is still hot. Let cool, then refrigerate for several hours until ready to glaze.
For glazing the cake
1Melt the glaze ingredients together in a bowl over a pan of simmering water (bain-marie), until the temperature reaches 113°F (45°C) on an instant-read thermometer.
2Blend with an immersion blender until smooth, strain through a fine-mesh sieve, and pour over the chilled cake.
Extracted from The Chef in a Truck: The Fabulous Culinary Odyssey of a French Pastry Chef in California by François Perret and Éric Nebot (Flammarion, 2021).
Photography © Bernhard Winkelmann.