Step 1
Step 1: Preheat the oven to 180C (356F). Combine the eggs and sugar in a heatproof bowl or a mixer bowl. Place the bowl in a water bath, and bring the temperature of the mixture to 50-55C (122 to 131F), stirring constantly with a whisk.
Step 2
Step 2: Whip the mixture: Place the bowl in a mixer or use a hand mixer, and whip the mass on high speed until it cools down to 25-30C (77 to 86F).
Step 3
Step 3: Mix the dry ingredients: Add the sifted flour mixed with the corn starch to the egg mass in 2 to 3 passes. Use a spatula to stir the mixture gently from the bottom to the top each time so as not to disturb the airy texture of the dough.
Step 4
Step 4: Prepare the baking sheet: Line the baking sheet with parchment, silicone or a Teflon mat, and spread the dough over it in an even layer about 2 cm (0.8 inch) thick. The biscuit doesn’t grow much, so you may set the thickness you want to get as a result.
Step 5
Step 5: Bake the sponge biscuit: Bake in the preheated oven to 180C (356F) for 13 to 15 minutes until cooked. The biscuit should bounce under your fingers and have a golden color. No wet marks should be left on a toothpick.
Step 6
Step 6: Cool and cut: Transfer the sponge biscuit layer to a wire rack for cooling. Cut out two circles with a diameter of 18cm (7 inch) and 16cm (6.3 inch) from the cooled biscuit.
Step 7
Step 7: Make the soaking syrup: Combine all the ingredients in a saucepan and bring it to a boil until the sugar dissolves completely. Let the syrup cool down before soaking the biscuit.
Step 8
Step 8: Prepare the mold: Prepare a mold with a diameter of 16cm (6.3 inch) for the filling. You may use a ring covered with foil or a special silicone mold.
Step 9
Step 9: Combine the strawberry ingredients: Place the strawberry puree, lemon juice, and diced strawberries in a saucepan. If the puree is frozen, melt it over low heat, without heating the mixture above 30C (86F).
Step 10
Step 10: Add sugar and pectin: Combine the sugar and pectin NH in a separate bowl. With the heat off, pour the mixture of sugar and pectin into the puree, constantly stirring the puree with a whisk. Turn on medium heat and bring the strawberry mix to a boil, stirring occasionally; simmer the compote for 15 seconds, and remove it from the heat.
Step 11
Step 11: Freeze the compote: Pour the strawberry compote into a mold and freeze until completely frozen.
Step 12
Step 12: Prepare the gelatin: Soak the sheet gelatin in any amount of cold water. If you use powdered gelatin, take 30 grams (1.05 oz) of cold water for 6 grams (0.20 oz) of gelatin.
Step 13
Step 13: Prepare the milk and vanilla: Heat the milk with the vanilla pod (don’t forget to remove the seeds) to a boil in a saucepan. Let it brew for 20 minutes.
Step 14
Step 14: Combine yolks, sugar, and cornstarch: Use a whisk to combine the egg yolks, sugar, and corn starch in a bowl.
Step 15
Step 15: Combine milk with the yolk mixture: Bring the milk to a boil once again and pour the hot milk into the yolks with sugar in a thin stream in three passes, stirring constantly with a whisk.
Step 16
Step 16: Cook the custard: Return the mixture to the saucepan, and place it over medium heat. Stir vigorously with a whisk and bring the mixture to a boil (thickening the cream); stir well to break all lumps, and boil for another 30 to 40 seconds.
Step 17
Step 17: Complete the custard: Remove from the heat, transfer immediately to another container, add the squeezed sheet gelatin or swollen powdered gelatin and cold butter pieces, and combine them completely. Cover the custard with foil in contact and refrigerate for at least 2 hours until it cools completely (up to 4C | 39F).
Step 18
Step 18: Finish the custard: When the custard has cooled and stabilized completely, remove the vanilla pod from the custard and whisk the custard to a homogeneous texture using a mixer with a whisk attachment. Add the very cold cream to the custard in three passes, keep whisking on medium speed; add the mascarpone, and whisk until the crème gets firm and keeps the shape. It should be smooth! Place the crème in a pastry bag.
Step 19
Step 19: Assemble the cake: Use a short ring with a diameter of 20 cm (7.9 inch). Be sure to cover its sides with acetate film. A biscuit with a diameter of 16 cm (6.3 inch) goes to the bottom and the 18 cm (7 inch) to the top. Be sure to soak both sponge biscuits with the lemon syrup. Put the finished cake in the fridge for 2 hours to stabilize. Enjoy cooking!