Preheat your oven to 190°C (375°F).
Peel and core the apples, then cut them in half.
In an oven-safe skillet, melt the butter over medium heat.
Add sugar and stir until it dissolves, forming a caramel.
Arrange the apple halves cut-side up in the caramel.
Cook for about 10 minutes until the apples begin to soften.
Drizzle vanilla extract over the apples.
Roll out the puff pastry and place it over the apples, tucking the edges in.
Bake in the preheated oven for 30-35 minutes until golden brown.
Let it cool for a few minutes, then carefully invert onto a plate.