Start by mixing the flour, salt and (room temperature) butter.
Mix the egg yolk with a little water, then add it to the dry ingredients.
Knead the dough for a few minutes, until it's even and soft. If it's too crumbly, you can add a tablespoon of cream.
Roll out the dough, and it's ready to use.
Preheat your oven to 150°C (300°F).
Peel the apples and slice them into eighths.
Pack them in a tin as tightly as possible.
To make the caramel, heat up the sugar mixed with a little water over medium heat. Be careful not to change the level of heat or stir it until the sugar begins to change color.
When the edges begin to brown, mix slowly by stirring from the edges to the middle.
When the sugar has completely browned, you can stir faster until your caramel reaches the color you desire.
Add in the pieces of butter, being careful not to splash or burn yourself.
Immediately pour the caramel over the apples.
Bake the apples in the oven at 150°C (300°F) for 1 hour.
Remove the tin and let it cool to room temperature.
When the apples have cooled, put the pie crust on top. Make sure to tuck in the edges and prick the crust to prevent it from inflating while cooking.
If you're using a puff pastry, don't forget to add a grid to keep it from rising too much.
Bake for 20 to 25 minutes, until the crust turns golden.
To avoid burning yourself, wait a little before removing the tart from the pan, but not too long, since the apples need to be a bit hot for easy removal. Flip over the tart onto a plate.
Your tarte tatin is ready. You can enjoy it warm or cold, as you like. You can serve it with vanilla ice cream or add a dollop of cream on top.