How to cook
Mix the butter and 1 cup of the sugar at the bottom of an oven dish. Put them in the oven to heat until caramelized. Then, using a spatula, smear it along the entire bottom.
Sprinkle with half the lemon zest. Peel the apples and cut them into crescents. Arrange them on top of the caramel. Instead of apples, you can use well-drained canned fruits - peaches, apricots, pears.
When you take the cake out, invert it while still warm. To the caramel left over in the oven dish, add 1 cup of water, bring it to a boil, stir until it dissolves and lightly syrup the cake with it.
You can also add compote juice or apple juice to the caramel syrup.