Mix the butter with the sugar.
Add the flour, with the baking powder.
Then mix in the egg yolks.
Mix until a homogeneous dough is created.
Turn the dough into a ball and cool down for one hour.
Then get 400 g of dough and roll it out to 1 cm larger than the baking tin.
Roll out the remaining of the dough into a circle with the same diameter as the baking tin.
Cover the bottom of the baking tin with baking paper and grease in with butter.
Place the dough in the tin and make an upright edge of 1 cm.
Spread then the caramel in the shape on the dough.
Place on the other slice of dough.
Press the edge gently and then put 2 hours in the refrigerator.
Brush the top of the cake with egg yolk and carve a breton pattern on the cake with a fork.
Bake for 45 minutes and leave to cool before taking the cake out of the tin.
The cake is at its best the next day!