Prepare Whipped Cream: In a chilled mixing bowl, combine heavy whipping cream, powdered sugar, and vanilla extract. Beat on medium-high speed until stiff peaks form, about 3 to 5 minutes.

Prepare Sponge Cake: Lay a sheet of parchment paper on your work surface and place the vanilla sponge cake on top. Trim the edges to create a neat rectangle.

Layer Filling: Spread a thin layer of strawberry jam over the sponge cake, then spoon a generous layer of whipped cream over the jam.

Add Strawberries: Slice fresh strawberries and arrange them along one edge of the sponge cake, placing them close together.

Roll Cake: Gently roll the cake using the parchment paper. Tuck the filling as you roll to keep it snug, forming a sushi-style log.

Chill: Wrap the rolled cake in plastic wrap and refrigerate for 45 to 60 minutes to help flavors meld together.

Slice and Serve: Unwrap the roll, slice it into 1-inch pieces using a sharp knife, and arrange on a serving platter. Drizzle with melted white chocolate if desired.