Makes about 6 cups, perfectly matching the requirement of GÉNOISE (Sponge Cake) ROLL
- 8 large egg yolks, plus 3 egg whites, room temperature
- 2 large eggs
- 1cup plus 3 tbsp plus 1 tsp sugar
- 1 tbsp plus 1 teaspoon finely grated lemon zest, plus 2/3 cup fresh lemon juice (3 to 4 lemons total)
- 2 tablespoons unsalted butter
- ¾ pound mascarpone cheese, room temperature
- 1 pint (2 cups) blackberries
Make lemon curd:
- Put egg yolks, eggs, 3/4 cup sugar, and lemon juice in a medium heatproof bowl; set over a pan of simmering water.
- Whisk until mixture is very thick and smooth and temperature registers 165° on an instant-read thermometer, thermometer, about 5 minutes.
- Remove from heat; whisk in butter.
- Pour through a fine sieve into a medium bowl; cover with plastic wrap, pressing wrap directly on surface of curd.
- Refrigerate until cool and firm, about 1 hour.
- Put egg whites in the bowl of an electric mixer fitted with the whisk attachment; beat on low speed.
- Meanwhile, bring 1/3 cup sugar and 2 tablespoons water to a boil in a small saucepan over high heat.
- Swirl pan to dissolve sugar.
- Wash down sides of pan with a wet pastry brush to prevent crystals from forming.
- Boil until syrup registers 248° on an instant-read thermometer.
- Raise mixer speed to medium high; beat until egg whites have formed almost-stiff peaks.
- With mixer running, slowly pour in syrup; beat until mixture has cooled and stiff, glossy peaks have formed, about 4 minutes.
- Set meringue aside.
- Stir mascarpone in a large non-reactive bowl with a rubber spatula until smooth.
- Fold in lemon curd and lemon zest.
- Fold in meringue.
- Pulse berries and remaining 2 tablespoons sugar in a food processor until berries are broken up but not smooth.
- Fold into lemon mixture, leaving it slightly swirled.
- Freeze until slightly firm, about 20 minutes. Use immediately.