Lemon Vanilla Sponge Roll

Ingredients:

Sponge cake

• Cooking spray
• 6 large eggs, room temperature, whites separated from yolks
• 0.5 tsp freshly squeezed lemon juice
• 1.5 cups powdered sugar + extra for sprinkling
• 1/4 cup vegetable oil
• 1/4 cup whole milk
• 1 vanilla bean, halved lengthwise and seeds scraped out
• 1 and 1/4 cups premium flour
• 0.5 tsp baking powder
• 1/4 teaspoon salt

Filling and glaze

• Whites of 5 large eggs
• 1 and 1/3 cups granulated sugar
• 1 vanilla bean, halved lengthwise and seeds scraped out
• A pinch of salt
• 330 g unsalted butter, cut into pieces, room temperature
• 1 tbsp finely grated lemon zest + 2 tbsp freshly squeezed lemon juice
• 0.5 tbsp. lemon curd

Preparation:

1. Bake the sponge cake:

   
   Preheat oven to 375°F (190°C). Spray a rimmed baking sheet or a 10 x 17-inch (27.5 x 42 cm) tart pan with cooking spray; line the bottom with parchment paper and spray it with cooking spray. In a large bowl, beat the egg whites and lemon juice with a mixer on medium speed until soft peaks form, about 3 minutes. Add 1/2 cup of powdered sugar. Increase the mixer speed to medium-high and beat until stiff peaks form, 3 to 4 minutes.
   
2. In a separate large bowl, whisk the egg yolks with the vegetable oil, milk, and vanilla seeds until smooth. Sift the remaining 1 cup sugar, flour, baking powder, and salt into a medium bowl; fold in the yolk mixture until smooth. Fold in about one-third of the beaten egg whites with a rubber spatula, then fold in the remaining egg whites in two additions. Pour the batter into the prepared pan; bake until the cake springs back when gently pressed, 12 to 14 minutes.
3. Generously sift powdered sugar over the hot sponge cake and loosen the edges with a knife. Place a clean kitchen towel (not terrycloth) on top of the cake. Place another baking sheet on the towel and invert the cake, along with the baking sheets, to place it on the towel. Remove the top baking sheet and parchment. Roll the cake along the short edge, using the towel as a log. Transfer the cake, seam-side down, to a wire rack and let cool completely.

4. Meanwhile, prepare the glaze:

   
   Whisk the egg whites, granulated sugar, vanilla seeds, and salt in a heatproof bowl set over a saucepan of simmering water (the bottom of the bowl should not touch the water). Heat, whisking until the sugar dissolves, 2-3 minutes. Transfer the bowl to a stand mixer and beat with the whisk attachment on medium-high speed until stiff peaks form, 6-8 minutes. Beat in the butter, 1 piece at a time (the mixture may look curdled). Add the lemon zest and juice. Switch to the whisk attachment and continue beating until smooth, about 2 minutes.
   
5. Carefully unroll the roll. Spread 2 cups of filling over the entire surface of the sponge, leaving a 0.5 cm border, and spread the lemon curd on top; lightly mix the two fillings. Roll the roll again (without the towel). Trim the ends with a serrated knife. Transfer the roll to a serving platter and spread the remaining glaze over the entire surface.