Grease the tart pan with butter, roll out the puff pastry, prick it with a fork, and chill in the refrigerator.

Whisk the eggs with the sugar until the mixture becomes light and frothy.

Add the vanilla sugar and softened butter, then whisk to combine.

Mix in the almond flour and stir until the mixture is smooth and even.

Peel, core, and slice the apples thinly.

Spread the almond cream evenly over the tart crust, then arrange the apple slices neatly on top.

Preheat your oven to 410°F (210°C), then bake for about 35 minutes, depending on your oven.

Let the tart cool slightly before removing from the pan.