A soft, moist vanilla sponge topped with a layer of mascarpone, tart jewel-like redcurrants, and a buttery golden streusel. Inspired by the beloved German Johannisbeer Streuselkuchen — and utterly irresistible.
INGREDIENTS
• 175 grams unsalted butter, softened
• 175 grams caster sugar
• 3 large eggs
• 1 teaspoons vanilla bean paste
• 175 grams self-raising flour
• 1 teaspoons baking powder
• 3 tablespoons tbsp milk
• 250 grams mascarpone
• 2 tablespoons tbsp icing sugar
• 1 lemon, zested and juiced
• 350 grams fresh redcurrants, stalks removed
• 1 tablespoons tbsp caster sugar for berries
• 120 grams plain flour for streusel
• 80 grams light brown sugar for streusel
• 80 grams cold unsalted butter, cubed, for streusel
• 0.5 teaspoons ground cinnamon for streusel
STEPS
1. Preheat oven: Preheat oven to 175°C (155°C fan). Grease and line a 23cm springform tin with baking paper.
2. Make the streusel: Make the streusel first: rub 120 grams plain flour for streusel, 80 grams light brown sugar for streusel, 80 grams cold unsalted butter, cubed, for streusel, and 0.5 teaspoons ground cinnamon for streusel together with your fingertips until the mixture forms rough, pea-sized clumps. Refrigerate until needed.
3. Macerate the redcurrants: Toss 350 grams fresh redcurrants, stalks removed with 1 tablespoons tbsp caster sugar for berries and the juice from 1 lemon, zested and juiced. Set aside to macerate while you make the batter.
4. Make the sponge batter: Beat 175 grams unsalted butter, softened and 175 grams caster sugar together until pale and fluffy, about 3–4 minutes. Add 3 large eggs one at a time, beating well after each. Mix in 1 teaspoons vanilla bean paste. Fold in 175 grams self-raising flour and 1 teaspoons baking powder, then stir in 3 tablespoons tbsp milk.
5. Add the mascarpone layer: Spread the sponge batter evenly into the lined tin. Mix 250 grams mascarpone with 2 tablespoons tbsp icing sugar and the zest from 1 lemon, zested and juiced until smooth, then dollop and gently spread over the batter — don’t mix it in.
6. Layer the fruit and streusel: Scatter the macerated 350 grams fresh redcurrants, stalks removed evenly over the mascarpone layer. Sprinkle the cold streusel generously over the top.
7. Bake: Bake for 50–60 minutes until the streusel is deep golden and a skewer inserted into the centre comes out clean. Check at 40 minutes and loosely cover with foil if the top is browning too quickly.
8. Cool and serve: Cool in the tin for 20 minutes before releasing from the springform. Serve warm or at room temperature, dusted with extra icing sugar if desired.
NOTES
The mascarpone layer is the twist that sets this apart from a standard streusel cake — it adds a luscious creaminess between the sponge and the fruit that makes every slice feel indulgent. Make sure the mascarpone is properly cold when it goes on, or it will sink into the batter. This cake is best eaten on the day it’s baked but keeps well covered in the fridge for up to 2 days.