I’d like to call this a sophisticated take on the classic strawberry-whipped-cream swiss roll (or “Biskuitroulade” as we Austrians love to call it). The sponge is light and airy, yet sturdy enough to hold the filling. And the filling is a delicious mixture of white chocolate, strawberries and mascarpone. A perfect Sunday afternoon bake or beautiful addition to your upcoming Easter spread!
- Prep Time: 30m
- Cook Time: 17m
- Total Time: 1h 30m
For the biscuit roll
- 1 tablespoon powdered sugar
- optional for garnishing: more strawberries, white chocolate (eggs), slices of lemon
- 6 eggs
- 100 grams (coconut blossom) sugar
- 2 tablespoons water
- 150 grams flour
- zest of 1/2 organic lemon
- pinch of salt
For the filling
- 500 grams strawberries
- 1 teaspoon agar agar (about 5g)
- 1 teaspoon ground vanilla bean
- 2 tablespoons (coconut blossom) sugar
- juice of 1/2 organic lemon
- 100 grams white chocolate
- 2 tablespoons cream or milk
- 500 grams mascarpone
For the sponge cake
- Preheat the oven to 170° Celsius and line a baking sheet with baking paper.
- Seperate the eggs into two very clean medium whipping bowls. Make sure no egg yolk accidentally drops into the egg whites.
- Start whipping the egg yolks on medium high until they start to become frothy. Once they start getting light and fluffy start adding the sugar slowly until it's fully incorporated. Add two tablespoons of water and the lemon zest and keep on whipping until the eggs are pale-yellow, about 3-5 minutes.
- Add a pinch of salt to the egg whites and whip until stiff (Make sure to properly clean the whisks).
- Now sift 1/2 of the flour into the egg yolks and incorporate carefully with a spatula. Then add 1/2 of the egg whites and to the same. Continue with the flour and lastly add the remaining egg whites.
- Transfer the batter onto the prepared baking sheet and carefully spread it into a rectangle.
- Bake for 15-17 minutes or until nice golden brown. When done let cool for a couple of minutes before flipping it onto a clean kitchen towel that you covered in powdered sugar before. Let cool completely before filling and rolling up.
For the filling
- While the sponge is baking, wash and clean the strawberries. Put 1/2 aside for the filling and garnishing and blend the other half until smooth.
- Add the agar agar to a small pot and mix with 2 tablespoons of the strawberry pulp until very smooth. Add the rest of the strawberry pulp and the vanilla. Slowly heat up over medium heat, stirring continuously until the mixture starts boiling. Cook for another 2 minutes. Then set aside to cool off a little.
- Add juice of the lemon and 1-3 tablespoons sugar (depending on the sweetness of the strawberries) to the strawberry mixture. And set aside.
- Break the white chocolate into pieces and place in a heat-proof bowl together with the milk or cream. Put the bowl over a small pot filled with 2cm of water. Bring to a simmer and slowly melt the chocolate until liquified.
- Place mascarpone in a medium bowl and whip through for 30-60 seconds. Slowly add the strawberry pulp and the white chocolate and whip until combined and smooth. Put in the fridge for at least 30 minutes before assembling the roll.
- Spread the strawberry-mascarpone cream onto the prepared sponge cake, reserving 2 tablespoons for garnishing. Cut reserved strawberries into pieces an place them onto the cream.
- Roll cake lengthwise into a long log. Place in the fridge for another 30 minutes (or up to 2 days).
- Garnish with the remaining cream, strawberries, white chocolate (eggs), slices of lemon and more powdered sugar, if you want to.
- Keep in the fridge and eat within 3 days!
- Notes: The filling can be made ahead up to 24 hours. Whip through before using.