Apple and vanilla babka

Preheat the oven to 200˚C, gas mark 6. Core and thinly slice 1 apple, sprinkling a little lemon juice over to stop it browning. Peel and roughly grate the remaining apples (to give 250-300g grated apple), sprinkling them with lemon juice too.

Use the butter to generously grease the base and sides of a 20cm baking tin or pie dish then sprinkle 1 tbsp sugar over the butter. Arrange the sliced apple over the base. In a large bowl, whisk the egg yolks with ½ the remaining sugar (about 70g) and the vanilla until foamy and voluminous. Whisk in the crème fraîche, then fold in the flour. Mix in the grated apples until well combined. In a second large, clean bowl, whisk the egg whites with a pinch of salt and the remaining 70g sugar until they reach soft peaks. Fold a spoonful of the egg whites into the apple mixture quite robustly, to loosen it. Then, carefully but confidently, fold in the rest of the egg whites until evenly combined.

Pour the mixture over the layered sliced apples and bake for 35-45 minutes. If the top starts browning too much, cover it with a piece of foil, but resist opening the oven for the first 15 minutes. When cooked, the pudding will be puffed-up and golden. Let it cool for at least 10 minutes. Serve warm or at room temperature, scooping it out with a large serving spoon, with some fresh blackberries and a little double cream or yogurt on the side.