I haven't made any kind of apple custard cake before, so it was just right to make for my family coming on Saturday. I've adapted the recipe as there wasn't a mention of what size tin to use; there rarely is in French recipes, simply says 'moule à manqué', a deep cake tin! G didn't say what apples she used, but I used Bramleys, as I didn't want the cake to be too sweet. She must have got the custard powder at the supermarket [but I always take of tin of it with me when I visit her, together with tea, marmalade and Marmite!]
Preheat oven 180C/gas4 Grease a 20cm springform tin and line base with baking paper
Make the custard for the cake first - mix together 2tbspn custard powder and 55g of caster sugar in a pan then slowly add 250ml of milk, whisking it in then slowly bring to the boil. Stir it over a medium heat till it thickens. Take it off the heat and add 20g butter and 2 tspn vanilla extract. Pour into a bowl and cover with some clingfilm and leave to cool.
Mix 40g custard powder together with 185g plain flour and 2 tspn baking powder. In another bowl beat together 200g butter and 110g caster sugar till nice and fluffy. Add 2 eggs, one at a time, then add the flour mixture, 1 tspn vanilla extract and 1-2 tbspn milk.
Peel core and thinly slice 3-4 medium Bramleys.
Spoon half of the cake batter into the tin and spread the cooled custard over the top. Drop the rest of the batter over the top in spoonfuls, and smooth gently to completely cover the custard. A little spatula is useful to do this.
Put the apple slices over the top of the batter, and sprinkle some cinnamon and demerara sugar over the top.
Bake for about 50 mins.