Heat the oven to 160C/140C fan/gas 3. Butter the base of a loose-bottomed 20cm cake tin that is at least 7cm deep. Line the base with baking parchment, then wrap a wide band of parchment around the outside of the tin and tie to secure, so the cake won’t burn.

Combine both types of nuts, the dates, sultanas and toffee in a bowl, then mix the flour, salt, sugar and almonds together in another bowl. Beat the butter, eggs, treacle and rum into the flour mixture with an electric whisk until smooth. Stir the fruit and nut mix into the wet ingredients, then gently fold through the dulce de leche to create a ripple effect. Spoon the mixture into the prepared tin and level with the back of a spoon. Bake for 1 hr, then reduce the oven to 150C/130C fan/gas 2. Cover the cake with a circle of baking parchment and bake for another 1 hr 25 mins, or until a skewer inserted in the middle comes out clean. Set aside (don’t remove from the tin) and increase the oven temperature to 200C/180C fan/gas 6.

To make the topping, gently heat the syrup and butter in a pan. Stir in the salt, pecans, hazelnuts, almonds and flour. Remove the parchment circle from the cake, then dot the surface with the topping and bake for 12-15 mins more until golden. Leave to cool in the tin, then remove and decorate with ribbon, if you like. Will keep in an airtight container for up to two weeks.