- Heat your oven to 160C.
- In a large bowl, beat butter with granulated and brown sugars until fluffy. Beat in eggs, sour cream and vanilla until smooth.
- Whisk together flour, baking powder, baking soda and salt; stir into butter mixture alternately with buttermilk, making 2 additions of dry ingredients and 1 of buttermilk.
- Place your peeled apples in rows in a large rectangle baking tray. Pour your batter over the apples then bake for 35-40 mins.
- Meanwhile, add your brown sugar, butter, salt, vanilla extract and cream to a small pan and bring to a boil, whisking all the while.
- Pour your caramel over the cake, carve into squares with an apple per slice and serve!