Famed London based chef, Ottolenghi, is no stranger to the obscure. Throughout his culinary career he has made a name for himself taking the most simple of ingredients + flavors, and combining them in unique + delicious ways.
When he released his cookbook, Sweet, a collaboration with longtime Ottolenghi pastry chef, Helen Goh, we knew that it would be just as exquisite. (After all is flourless chocolate cake from Ottolenghi The Cookbook is to die for!)
Combining light + zesty lemon sponge with blackcurrant buttercream, this recipe is equal parts light + rich in it's depth of flavor all at the same time. As Ottolenghi says, "this is a testament to what a showstopper a simple sponge and buttercream can be."
- 8 large eggs, separated
- 3/4 cup (163g) granulated sugar, divided
- 1 tablespoon (14g) lemon juice, fresh preferred
- 1/2 cup + 3 tablespoons (81g) All Purpose Flour
- 1/8 teaspoon salt
- 1 teaspoon lemon zest (grated rind)
- confectioners' sugar, for dusting
- 2 cups (283g) black currants or mixed frozen berries
- 1/4 cup (50g) granulated sugar
- 1/4 cup (78g) light corn syrup or golden syrup
- 1/2 cup + 1 tablespoon (113g) granulated sugar
- 1 teaspoon vanilla bean paste, or scraped seeds of 1/2 vanilla bean
- 4 large egg yolks
- 21 tablespoons (298g) unsalted butter, at room temperature, cut in cubes
- Preheat the oven to 400°F. Line an ungreased 13" x 18" half-sheet pan with parchment.
- To make the cake: Place the egg yolks in the bowl of a stand mixer fitted with the whisk attachment. (Reserve the whites, holding them at room temperature.) Measure 1 1/2 tablespoons of the sugar and set aside; add the remaining 3/4 cup sugar to the egg yolks along with the lemon juice.
- Beat on medium-high speed for about 3 minutes, until the mixture is pale yellow and thick. Remove the bowl from the mixer and sift half of the flour plus the salt over the yolk mixture.
- Fold the flour into the mixture, taking care not to deflate it, and repeat with the remaining flour and salt. Add the lemon zest and transfer to a large mixing bowl.
- In the clean bowl of your stand mixer fitted with the whisk, beat the egg whites on medium-high speed until soft peaks form, then slowly pour in the reserved 1 1/2 tablespoons sugar. Beat until stiff peaks form.
- Gently fold one-third of the beaten egg whites into the egg yolk mixture. Fold in the remaining egg whites until the batter is uniform in color but still puffy. Transfer the mixture to the prepared baking sheet, spreading it all the way to the edges; level the top with an offset spatula.
- Bake the cake for 15 minutes, until it's light golden brown and a cake tester or toothpick inserted in the center comes out clean. Remove it from the oven and cool on a rack for five minutes.
- When the cake is barely warm, dust the top with confectioners' sugar and place a clean tea towel over the top. Put another baking sheet over the towel, pick up the whole stack, and flip the cake over.
- Remove the pan and carefully peel the parchment off the cake. With a long serrated knife, carefully trim the very edges of the sponge. Starting at the short end of the cake, use the towel to roll it up (towel included). This "trains" the cake to roll up later without cracking.
- After 20 minutes, when the cake is completely cool, unroll the cake, and with the short end facing you, cut the cake in thirds parallel to the long edge. Cover the strips with the towel and set aside.
- To make the purée: Place the berries and sugar in a medium saucepan over medium heat. Heat, stirring occasionally, until the berries soften and the sugar dissolves. Purée with an immersion blender, then pour through a fine-mesh strainer into a bowl, pressing with a spatula to push the pulp through. Measure out 2/3 cup of the purée and keep the rest for another use.
- To make the buttercream: Place the corn syrup (or golden syrup) in a small saucepan with the sugar and scraped seeds of the vanilla bean (or vanilla bean paste). Place over low heat and stir just until the sugar dissolves; stop stirring, but keep cooking.
- While the sugar is cooking, place the egg yolks in the bowl of a stand mixer fitted with a whisk. Beat on medium-high speed until thick and pale yellow. Leave the mixer running while you check the syrup.
- Increase the heat to medium and cook until the syrup reaches a temperature of 245°F and there are large bubbles all over the surface. Remove the pan from the heat and carefully pour it down the edge of the mixer into the beating yolks.
- When all of the syrup has been added, increase the mixer's speed to high and continue to beat for about 10 minutes, until the outside of the bowl is no longer warm to the touch.
- Add the butter one cube at a time, beating until each piece is incorporated before adding the next. When all the butter is added, scrape the sides and bottom of the bowl and beat for one more minute, until the buttercream is smooth and light.
- Add a scant 1/2 cup of the purée and beat on medium speed until the frosting is a uniform color.
- To assemble: Spread each of the cake strips with a slightly mounded 1/3 cup of frosting. Starting with the short end of one strip, roll it up. Place another strip at the tail end of the roll, butting the edges together and putting a little frosting over the seam. Continue to roll, and repeat with the last strip of cake. Turn your spiral on its side so the cut edge is sitting on a serving plate.
- Spread the remaining buttercream over the top and sides of the cake, smoothing the surface with an offset spatula. Cover the cake and store it in the refrigerator.
- To serve: Remove the cake from the refrigerator 45 minutes before serving to bring it to room temperature. Drizzle the remaining purée over the top of the cake and garnish with fresh berries.
- Store cake, covered, in the refrigerator for up to one week; freeze for longer storage.