How to cook
Mix the flour and powdered sugar in a bowl. Cut the butter into pieces, and them to the mixture and rub with your fingers, until crumbs are obtained.
Crack the egg and use it to combine the butter crumbs to form a dough. Knead it, until it becomes smooth.
Roll it out into 10 crusts with a diameter of about 4.5″ (12 cm) and put each in a 3.5″ (9 cm) diameter tart tin, by pressing the dough well on the bottom and sides. You can do it without rolling it out, by placing the ball of dough in the tart tin and spreading it out with your fingers.
Pierce the bottom with a fork and leave the ten tart tins in the freezer for 10-15 minutes.
Heat the oven to 360°F (180°C). Brush the cold hardened dough in the tart tins with beaten egg white and bake for 15-16 minutes. Leave them to cool down and prepare the cream.
Grate the lemon peel into the sugar, by using a fine citrus grater. Pour the cream and heat it for 3 minutes at 190°F (90°C) on low heat. During this time, hydrate the gelatin in cold water for 2 minutes.
Put the mascarpone and strained gelatin into the warm but not hot cream. Mix, until a smooth mixture is obtained and fill the tartlets with the cream.
When they cool, put them in the refrigerator for 2 hours to harden.
Just before serving these uniquely delicious spring tartlets, garnish them with spring fruit pieces of your choice.