Knead the flour, icing sugar, almonds, 1 egg and butter in pieces to a dough. Wrap in foil and chill for at least 30 minutes. Wash the lemons, grate them dry and finely grate the peel. Squeeze the lemons. Separate 3 eggs. Whisk egg yolks with sugar. Stir in starch, lemon peel and lemon juice
Boil 250 ml of water. Gradually stir into the lemon mixture. Return to the pot and bring to the boil while stirring. Pour the cream into a bowl and let it cool down while stirring occasionally
Grease a rectangular tart mould with lift-off base (19 x 27 cm). Roll out the dough on a floured work surface in a rectangular shape (21 x 29 cm) and line the mould with it, pressing the edges down. Weigh down with baking paper and dried peas and pre-bake in the preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for approx. 10 minutes. Remove baking parchment and peas and bake for another 10 minutes. Take out and let cool on a cake rack
Cream the mascarpone with the whisk of the hand mixer. Beat the egg white until stiff. Alternately fold mascarpone and beaten egg white into the lemon cream. Lift the tart base out of the mould. Spread the cream on the tarte base and chill for about 1 hour. Sort the raspberries. Puree 50 g raspberries and 1 tsp. icing sugar and pass through a sieve. Spread the raspberries over the tart. Drizzle the puree over the raspberries
waiting time approx. 2 1/4 hours