Prepare the Sponge Cake:

1. 1. Preheat the Oven: Preheat your oven to 350°F (175°C). Line a 10×15-inch baking sheet with parchment paper, making sure the paper covers the edges for easy removal after baking.

1. 1. Whisk the Eggs and Sugar: In a large mixing bowl, beat the eggs and granulated sugar together using an electric mixer on medium-high speed. Whisk for about 5-7 minutes until the mixture becomes pale, thick, and doubles in volume.

1. 1. Add Vanilla: Stir in the vanilla extract until well incorporated.

1. 1. Sift the Dry Ingredients: In a separate bowl, sift the flour, baking powder, and salt together to ensure even distribution of the dry ingredients.

1. 1. Fold in Dry Ingredients: Gradually fold the dry ingredients into the egg mixture using a spatula. Be gentle to avoid deflating the batter. Fold until just combined.

1. 1. Bake the Cake: Pour the batter onto the prepared baking sheet and spread it evenly. Bake for 12-15 minutes or until the cake springs back when touched, and a toothpick inserted comes out clean.

1. 1. Cool the Cake: Immediately after baking, turn the cake out onto a clean kitchen towel dusted with powdered sugar. Carefully peel off the parchment paper. Start rolling the cake up with the towel from one short end. Let it cool completely while still rolled up.

Prepare the White Chocolate Ganache Filling:

8. 8. Melt the White Chocolate: Place the chopped white chocolate and heavy cream in a heatproof bowl. Microwave in 20-second intervals, stirring in between, until the chocolate is melted and smooth. Add the vanilla extract and stir until fully combined.

8. 8. Cool the Ganache: Let the ganache cool to room temperature, then refrigerate for about 30 minutes until it thickens to a spreadable consistency.

Prepare the Raspberry Puree:

10. 10. Cook the Raspberries: In a saucepan, combine the raspberries, sugar, and lemon juice. Heat over medium heat, stirring occasionally, until the raspberries release their juices and soften (about 5 minutes).

10. 10. Strain the Puree: Once the raspberries have broken down, strain the mixture through a fine mesh sieve to remove the seeds. Let the puree cool completely.

Assemble

12. 12. Unroll the Sponge Cake: Once the cake has cooled, carefully unroll it from the towel. You should now have a flat, soft sponge.

12. 12. Spread the Ganache: Using a spatula, spread a generous layer of the white chocolate ganache over the surface of the cake, leaving a small border at the edges.

12. 12. Add the Raspberry Puree: Drizzle or spread the raspberry puree evenly over the ganache.

12. 12. Roll the Cake: Carefully roll the cake back up, starting from one short edge, using the parchment paper to guide you. Roll tightly but gently to avoid cracking.

12. 12. Chill the Cake Roll: Wrap the rolled cake in plastic wrap and refrigerate for 30 minutes to 1 hour, allowing the ganache to set and the flavors to meld.

Slice and Serve:

17. 17. Slice and Serve: Once chilled, slice the cake roll into thick pieces. Serve chilled or at room temperature. Garnish with extra raspberries or a light dusting of powdered sugar if desired.