Peel and halve the apples, then slice them thinly. Submerge the slices in cold water to prevent browning while you blend two of them into a smooth sauce.

Separate the egg yolks and whites. Beat the whites until stiff peaks form. In a separate bowl, mix yolks with sugar until pale. Add oil, milk, apple sauce, and vanilla, then gradually blend in sifted flour, baking powder, and pudding.

Gently fold the beaten egg whites into the batter.

In a heavy-bottomed pot over medium heat, melt the sugar until it’s fully dissolved and golden. Stir in the butter until melted, then pour this caramel into a buttered springform pan.

Layer the sliced apples over the caramel in the pan, sprinkle with cinnamon, and carefully pour the batter on top.

Bake in a preheated oven at 360°F (180°C) for about 50 minutes.

Once baked, invert the pie onto a plate while it’s still hot, then allow it to cool slightly before serving.