Preheat your oven to 350°F (175°C). In a large mixing bowl, whisk together the eggs and granulated sugar until pale and fluffy (about 5 minutes). Add vanilla and mix well. In another bowl, combine flour, baking powder, and salt, then fold into the egg mixture.

Line a baking sheet with parchment paper and spread the sponge batter evenly. Bake for approximately 12 minutes or until lightly golden.

Let the cake cool in the pan for about 5 minutes. Flip onto a clean kitchen towel dusted with powdered sugar and roll tightly with the towel. Allow to cool completely in this rolled shape.

Whip heavy cream until stiff peaks form (about 3-4 minutes). Combine melted white chocolate and mascarpone, stirring until smooth. Gently fold the whipped cream into the chocolate mixture.

Unroll the sponge cake, spread the filling evenly, and drizzle raspberry sauce on top. Roll back up tightly and place seam-side down on a platter.

Wrap in plastic wrap and refrigerate for at least 1 hour to set the filling.

Before serving, dust with powdered sugar and optionally drizzle with more raspberry sauce or garnish with white chocolate curls.