Step 1
Preheat the oven to 400 degrees F (200 degrees C). Line a baking sheet with parchment paper.
Step 2
Combine egg yolks 1/2 cup sugar and 2 teaspoons vanilla sugar in a large bowl; beat with an electric mixer until foamy.
Step 3
Beat egg whites in a glass metal or ceramic bowl until foamy. Gradually add confectioners' sugar continuing to beat until stiff peaks form. Slide over the egg yolk mixture.
Step 4
Sift flour and baking powder over the stiff egg whites. Carefully fold everything into the egg yolk mixture until batter is well combined but do not over mix. Spread batter onto the prepared baking sheet.
Step 5
Bake in the preheated oven until sponge cake is set and lightly browned 12 to 16 minutes.
Step 6
Lay a clean dish towel on a flat work surface and sprinkle dish towel with 2 teaspoons sugar. Invert sponge cake onto the dish towel and remove parchment paper. Roll up cake with the dish towel and allow to cool completely about 1 hour.
Step 7
Beat 3/4 cups cream in a chilled glass or metal bowl with an electric mixer until frothy. Add vanilla sugar gradually continuing to beat until stiff peaks form. Fold in strawberries with a spatula.
Step 8
Carefully unroll sponge cake. Spread strawberry cream on top leaving a little room on the edges. Carefully roll up and place seam down onto a cake platter. Allow to chill in the refrigerator for 1 hour.
Step 9
Beat 1/2 cup cream in a chilled glass or metal bowl with an electric mixer until frothy. Add vanilla sugar gradually continuing to beat until stiff peaks form. Spread all over the strawberry roll and garnish with strawberry halves.