Pre-heat oven to 180-200°C.

Place the butter and caster sugar into a heavy-bottomed cake tin and place the tin on the hob. Heat until the caramel reaches the desired colour (light or dark). Remove from the heat. 

Peel, core and halve the apples.

Arrange the apple halves on the cooled caramel and sprinkle with cinnamon (if using). 

To speed up the cooking time of the apples, cover them with kitchen foil and cook over a high heat for 5 – 10 mins. 

Dust the work surface with flour and roll the shortcrust pastry into a circle around 3 or 4 mm thick. It should be slightly larger in diameter than your cake tin. 

Cover the apples with pastry, tucking the edges inside the tin. 

Bake in a hot oven until the pastry is cooked through (25 – 30 minutes).

Remove from the oven. Cover the cake tin with a larger tin; invert and release the tart from its tin while still warm.