Apple crumble cake

When we came to France nearly 7 years ago, we brought 2 Bramley apple trees with us, as the variety isn't known here. They've been prolific and have given us apples for the freezer every year.
I'm always looking for new recipes to use them and found this one in an old exercise book that I used in a cookery evening class in the 70s.

100g soft margarine or butter
100g caster sugar
1 tspn vanilla extract
2 eggs beaten
150g sr flour
milk if needed
350g apples, peeled, cored and sliced [and defrosted if frozen]
topping
75g hard margarine [I used soft]
100g sr flour
75g caster sugar
1 tbspn water
Preheat oven 180C/350F/gas 4
Make the cake first by creaming the fat and sugar till light and fluffy then beating in the vanilla and eggs.
Fold flour into the mixture and if necessary add a little milk to make a stiffish dropping consistency.
Grease a 21cm loose-bottomed tin and line base with parchment.
Put cake mixture into tin and smooth top, then put the apple on top in a layer.
Make topping by rubbing fat into flour and stirring in the sugar and water.
Spoon this over the apple.
Bake for about an hour - check after 45 mins as the top was golden, but the bottom wasn't cooked, so I covered the top in foil and cooked it for another 15 mins.

Serve it hot with cream or ice cream or cold as a cake.
It makes a substantial sized cake!