Tom's Autumn Apple Cake

I copied this recipe down a long time ago, and I think I forgot to halve the apples along with the rest of the ingredients.  If you like apples a lot use the full amount (I did for my bake, and it works), but it turns out very apple-y!

It's gluten free, but probably also works fine with normal plain flour. But then obviously wouldn't be gluten-free.

Ingredients

1lb peeled, cored and sliced apples
1½ cups GF flour (or Polenta)
½ tbsp GF baking powder
Pinch salt
1¼ cups granulated sugar (I used brown)
½ cup oil
2 large eggs
1½ tsp Vanilla
Zest and juice of 1 small orange

Method

Put the everything except the apples in a bowl and mix it together well.
Line a 8" square tin and pour in half the batter.
Layer on half the apples.
Pour on remaining batter.
Layer on remaining apples.
Sprinkle some brown sugar and little pinch of cinnamon over the apples.
Bake for around 1½ hours at 180°C/GM4.