Equipment
Ingredients
Cranberry Puree
- 300 g cranberries, fresh or frozen
- 100 g granulated sugar
- 30 ml water
Lemon Sponge
- 6 eggs, room temperature
- 150 g caster sugar
- 120 g cake flour
- 2 g salt
- 50 ml whole milk
- 50 ml neutral oil
- 10 g lemon zest, finely grated
Cranberry Mascarpone Filling
- 250 g mascarpone cheese, cold
- 150 ml heavy cream, cold
- 50 g powdered sugar, sifted
Lemon Buttercream Exterior
- 200 g unsalted butter, room temperature
- 200 g powdered sugar, sifted
- 30 ml lemon juice, freshly squeezed
Nutrition (per serving)
Method
Preheat the oven to 190°C (375°F). Line a 33x45cm half sheet pan with parchment paper, ensuring the paper extends slightly up the sides.
Combine the cranberries, granulated sugar, and water in a saucepan. Simmer over medium heat until the berries burst and the mixture thickens. Blend into a smooth puree and set aside to cool completely.
In a stand mixer, whip the eggs and caster sugar on high speed until the mixture is pale, thick, and has tripled in volume, reaching the ribbon stage.
Gently fold the sifted cake flour and salt into the whipped eggs in three additions to maintain aeration. In a small bowl, whisk together the milk, oil, and lemon zest, then fold this liquid mixture gently into the batter.
Pour the batter into the prepared half sheet pan, spreading it evenly to the edges with an offset spatula. Bake at 190°C (375°F) for 10 to 12 minutes.
Turn the warm cake out onto a clean piece of parchment paper. Carefully peel off the baking parchment. Immediately drape a clean kitchen towel over the sponge to trap the steam, allowing it to cool completely while remaining flexible.
In a stand mixer, whip the cold mascarpone, heavy cream, and 50g of powdered sugar until stiff peaks form. Gently fold in 150g of the cooled cranberry puree to create a vibrant pink, stable filling.
Using a serrated knife, cut the cooled sponge cake lengthwise into three equal strips, each approximately 11cm wide.
Spread the pink cranberry filling in an even layer across the three cake strips, leaving a small 1cm border at the edges to prevent the filling from squeezing out during rolling.
Roll the first strip tightly into a coil. Stand it upright on a flat serving platter. Carefully pick up the second strip and wrap it around the first, matching the seams. Repeat with the third strip to create a large, continuous spiral.
Whip the room temperature butter, 200g of powdered sugar, and lemon juice until completely smooth, pale, and fluffy to create the exterior frosting.
Frost the top and sides of the upright spiral cake with the lemon buttercream, smoothing the edges with an offset spatula.
Refrigerate the fully assembled cake for at least 3 hours to allow the mascarpone filling and buttercream to set completely, ensuring clean vertical slices.
Chef's Notes
- A flexible sponge relies entirely on trapped moisture. Never skip covering the cake with a towel or parchment paper immediately after it comes out of the oven.
- Applying a very thin crumb coat of buttercream before the final frosting helps lock in the shape of the spiral and catches any errant pink crumbs.
- For the cleanest vertical slices that highlight the striking pink stripes, chill the cake thoroughly and use a sharp, warm serrated knife wiped perfectly clean between every single cut.
Storage
Refrigerator: 4 days — Keep in an airtight cake dome to prevent the buttercream from absorbing fridge odors.
Freezer: 1 month — Freeze whole or in individual slices wrapped tightly in plastic wrap.
