For the sablé:
Mix the flour, baking powder, vanilla seeds, almond powder, and sugar.
“Sand” the dry ingredients with the butter, that is to say by rolling the dough between your hands (you must work quickly, so the butter doesn’t melt), until you get a dough with a sandy texture, but homogeneous.
Add the egg yolks, knead one last time, cover the dough with a clean cloth, and let it rest for 15 minutes in the refrigerator.
Roll out the dough in a mold with a removable bottom, working it with your fingers.
Bake in a preheated oven at 300 F (150 C) for 20 to 25 minutes, or until the dough starts to brown.
Let it cool before unmolding.

For the apple compote:
Put the apples to cook in a saucepan with a little water (so they don’t stick at the beginning of cooking) and the sugar for about 15 minutes, or until the apples are tender.
Set aside without crushing them.

Assembly:
Spread the apple compote over the cooled dough.
Add the quince slices on top of the apples, then brush with quince cooking syrup.