Dough: In a blender, combine flour, 2 eggs, water and salt. Then knead dough by hand until smooth; cover the dough and let it rest for 30 minutes.
Filling: whisk together butter, sugar, lemon zest and lemon juice. Incorporate the egg yolks one by one, then the fromage frais, almond paste and crumbled biscuits. Cover and set in the fridge for 30 min.
To make the Maultaschen: Roll out the dough as thin as you can. With a round pastry cutter, cut an even number of circles. Place a tablespoon size dollops of the filling in on half of the circles but the edges empty. Brush a little egg white around each dollop. When half of circles are dotted with filling, cover with the remaining sheets of dough. Using your fingers, gently press dough to seal the maultaschen.
Cook the Maultaschen in boiling water for about 4 minutes or until they float to the top. Drain well.