Strawberry sponge cake roll

Preparation

• 1
  Separate the eggs and beat the yolks with warm water until foamy. Add vanilla sugar and 80 g sugar. Sift the flour, cornstarch and baking powder, add the Kölln instant oat flakes and stir carefully into the mixture. Also add butter to the dough and stir. Beat the egg whites with the remaining sugar until stiff and fold in carefully. Line a baking sheet with parchment and spread the dough onto it. Bake the sponge cake on the middle shelf for 8-10 minutes until golden brown.
• 2
  For the filling, soak gelatine in cold water. Reserve 2-3 strawberries for garnish. Cut the remaining strawberries, bring to the boil in a pot with the lime juice and sugar and simmer for about 5 minutes. Remove strawberries from heat and let cool for 3 minutes. Dissolve the squeezed gelatine in it and let the strawberry mixture solidify in the refrigerator.
• 3
  Sprinkle a thin layer of sugar on a tea towel and turn the sponge cake onto it. Remove the baking paper, use the towel to loosely roll up the sponge cake from the long side and let it cool.
• 4
  Whip the cream and fold it into the now slightly thickened strawberry mixture. Carefully roll back the sponge cake, spread it with the cream and roll it up again. Let the finished Swiss roll rest in the fridge for an hour. Just before serving, sprinkle with powdered sugar and garnish with the remaining strawberries.
• 5
  Top/bottom heat: 220 °C Circulating air: 200 °C Baking time: 8-10 minutes