Coat a 24 cm pie tin with butter and set aside.
Prepare almond cream, frangipane. Mix sugar and softened butter. Stir until well combined and until you get a frothy cream. You can use a mixer or a hand mixer.
Add one egg at a time so that it blends well with the mixture before continuing.
Add the sifted flour and mix until it becomes a fine cream.
Add the sliced almonds and combine with a spatula.
Roll out the dough and place in a mold.
Preheat the oven to 190 ° C.
Pour the frangipane over the dough.
Whisk in the egg whites. Pour the egg whites into a dry, deep glass bowl, start stirring with a mixer on medium speed, add the juice of half a lemon, and gradually add the sugar.
Stir until you get a firm, creamy egg white snow.
Add the egg whites over the frangipane cream and sprinkle with the almond pieces.
Bake at 190 ° C for about 25 minutes.
After baking, leave the pie to cool.