Preheat the oven to 180C (160C fan) and line an 8x10" baking tray with non-stick baking paper

Peel and dice your apples, then whisk together the sugar and cinnamon in a small bowl. Coat the apples in the mix, then set aside

In a small bowl, whisk together the sugar, cinnamon, and melted butter with a spoon until fully combined, then set aside

In a large mixing bowl, add the flour, sugar, and baking powder, then whisk together with a hand whisk unhtil combined

Pour in the milk, vanilla extract, and eggs and whisk until just combined, then gently stir in the butter with a wooden spoon or rubber spatula

Fold in your apples, then pour the batter into your prepared tin, spreading it out to the edges

Dollop on the cinnamon mixture (it may need a quick stir if it's separated), then swirl it through the batter with a knife. It should sit on top of the batter, rather than sink to the bottom

Bake for 40-45 minutes until a toothpick inserted into the cake comes out mostly clean, with just a few crumbs on it. The cinnamon swirl part should still be wet and gooey whilst it's hot

Whilst the cake is baking, make the glaze. Mix together the icing sugar and milk with a spoon until runny and smooth.

Pour the glaze over the warm cake and spread it out evenly, letting it drip down any cracks in the cake (this is the best part to eat!)

Let it cool in the tin for around 45 minutes, then slice into 16-20 pieces and enjoy warm or cold