Been given an excess of shortbread for Christmas? Got a surfeit of digestives? Put them in a food processor and blitz blitz blitz. Leave the motor running for a full 2 minutes — it will warm the mix and encourage the fat to break out and create a smooth, paste. If you like, add some honey or maple syrup for sweetness, viscosity and shine. Some incredibly naughty people have been known to drizzle melted butter in while they are blending (like a cheesecake base). If you’d like something really smooth you will have to add a drizzle of vegetable oil. We like rapeseed.