Lemon curd:

Cup of Yum
1. Combine: Wash and dry the lemons and finely grate the zest. Juice the lemons as well. Place the lemon zest and juice into a saucepan. Add the eggs, cornstarch, sugar, and water.
2. Cook: Gently bring to a simmer, lower the heat and whisk continuously. It will take about 5 minutes until the curd thickens. Let bubble for a couple of seconds, then remove from the heat.
3. Cool: Place a piece of cling film directly over the top of the curd to avoid it from getting a skin. Let cool completely.

Cake base:

1. Preheat the oven to 200 degrees Celsius/ 400 degrees Fahrenheit. Line a baking tray with baking paper.
2. Separate the eggs. Beat the egg whites with a pinch of salt until stiff. Set aside.
3. In another bowl, beat the egg yolks and water until frothy. Add the sugar and vanilla extract and continue beating until the mixture thickens, about 3 minutes.
4. Batter: Carefully fold the egg whites into the egg yolks. Sieve the flour over this mixture and fold it in carefully.
5. Bake: Pour the batter on the prepared baking tray and bake for about 12 minutes or until golden. In the meantime, place a clean kitchen towel on the table and sprinkle it with some sugar. Carefully turn out the cake base onto this towel. Remove the baking paper. Let the cake cool completely.

Prepare the flling:

1. Curd: When the lemon curd is completely cool, beat it very shortly with an electric mixer.
2. Whip ¾ of the heavy cream (keep the rest for whipping up later and decorating the cake squares). Carefully fold the whipped cream into the lemon curd. Place the filling in the fridge for about 10-15 minutes.
3. Prepare rasberries: In the meantime, wash and dry the raspberries. Set 12 nice ones aside for decoration purposes.

Assemble the cake:

1. Halve the cake base in the middle to obtain two equal parts. Place one cake slice on a rectangular serving platter.
2. Spread ½ of the filling on top and add the raspberries, cover them with the remaining lemon curd filling and place the second cake slice on top. Refrigerate for about 2-3 hours before serving.

Decorate cake:

1. Cut: Just before serving cut the cake into squares.
2. Beat the remaining cream, place it in a piping bag, and pipe cream rosettes on the cake squares.
3. Place a raspberry on top of each rosette. Sprinkle the cake with some icing sugar.