Heat the oven to 160C/140C fan/gas 3. Butter a deep 20cm cake tin and line the base and sides with baking parchment. Beat the butter and both sugars together using an electric whisk until light and fluffy. Slowly drizzle in the beaten egg, beating continuously. Sift the flour, ground almonds and mixed spice together, then fold this into the cake batter, a third at a time. Gently fold through the orange zest, mincemeat and cherries, if using.

Spoon the batter into the tin, level the surface and sprinkle over the demerara sugar. Scatter over the flaked almonds, if using. Bake for 1 hr-1 hr 15 mins, or until golden, firm and a skewer inserted into the middle comes out clean. If there is still raw batter, cover loosely with foil to prevent burning, and return to the oven for another 5-10 mins. Leave to cool in the tin for 15 mins, then lift out onto a wire rack to cool completely. Will keep in an airtight container for five days.