Preheat the oven to 180C/350F and line a cake tin with greaseproof paper.
Toss the butter and sugar into a bowl and whip until pale and fluffy, approximately 3 minutes.
Toss the flour and baking powder into a separate small bowl and stir to combine.
Add ⅓ of the eggs and flour mixture and whip on the lowest setting until combined.
Repeat adding in another ⅓ of the eggs and flour in portions, until smooth and no dry portions remain in the base of the bowl.
Stir in the apple and lemon zest until combined.
Spoon into your prepared tin and smooth out.
(Optional) You can choose to throw in all the apples into the batter or you can top the cake with ½ the apples for a bit more of a visual detail to the cake.
Sprinkle over the sugar and spices.
Bake for 1 hour, until golden and the edges are beginning to pull away from the tin.
Allow to cool before topping with an optional sprinkle of powdered sugar.
Slice, serve and dig in!