Instructions

1. For the syllabub: Put wine, sherry, and lemon zest and juice into a large bowl, stir to combine, cover with plastic wrap, and refrigerate overnight.
2. Make the custard: Bring milk to a boil in a medium pot over medium-high heat. Meanwhile, put eggs, egg yolks, and 1⁄4 cup sugar into a large bowl and whisk to combine. Slowly pour milk into bowl while whisking constantly to prevent eggs from scrambling. Transfer mixture to the pot and cook over medium-low heat, stirring constantly, until thickened, 12–14 minutes. Strain custard into a medium bowl; set aside to let cool.
3. Make the sponge cakes: Preheat oven to 350°. Line 2 baking sheets with parchment paper; set aside. Put egg yolks and 3⁄4 cup of the sugar into a large bowl and whisk until thick and pale yellow. In another large bowl, beat egg whites to stiff peaks. Add remaining sugar to egg whites and whisk again to stiff peaks. Add 1⁄3 of the egg whites, 1⁄3 of the flour, and 1⁄3 of the butter to egg yolk mixture and gently fold together. Repeat two more times with remaining egg whites, flour, and butter. Spoon a heaping 1⁄4 cup of batter onto a prepared baking sheet. Repeat to make 8 large circles in all, evenly spaced apart, 4 on each baking sheet. Bake until cakes are light golden brown and bounce back when touched, 13–14 minutes. Transfer to a rack to let cool.
4. To assemble: Place 4 sponge cakes in the bottom of a 14-cup glass bowl, overlapping them slightly. Pour half of the wine and half of the sherry over cakes; press firmly to soak up liquid. Repeat with remaining cakes, wine, and sherry. Top cakes with 5 cups of the raspberries; pour custard over raspberries. Cover with plastic wrap and refrigerate for 6–8 hours or overnight.
5. Finish the syllabub: Remove and discard zest from mixture, add remaining 1⁄3 cup superfine sugar, and stir to dissolve. Add cream and beat to soft peaks. Top trifle with syllabub, then heap remaining raspberries on top. Serve immediately.