Choose a new cookbook worth up to £28 when you subscribe to our magazine.
Heat oven to 180C/160C fan/gas 4. Put the flour, almonds, cocoa, caster sugar and a large pinch of salt into a food processor and whizz briefly. Add the butter and whizz until the mixture resembles damp sand.
Generously butter the base and sides of a small (15 x 25cm) baking tin. Tip the mixture into the tin and press it down. Bake for 30 mins. Remove from the oven, sprinkle over some demerara sugar and cut into squares using a sharp knife while still it’s soft.
Meanwhile, heat the caramel and cream together in a pan. Serve the concrete warm with the caramel sauce. You can cool any leftovers and eat them cold – they will harden like shortbread.