Step 1. Preheat the Oven and Prepare the Pan

Preheat your oven to 150°C (300°F). Grease an 8-inch round cake pan and line it with parchment paper, extending the paper above the rim to prevent over-browning.

Step 2. Cream Butter and Sugar

In a large mixing bowl, beat the softened butter and light brown sugar together until light and fluffy, about 3-5 minutes.

Step 3. Add Eggs Gradually

Add the eggs one at a time, mixing well after each addition to prevent curdling.

Step 4. Add Treacle and Zest

Stir in the black treacle, lemon zest, and orange zest, mixing until fully combined.

Step 5. Combine Dry Ingredients and Fruits

In a separate bowl, combine the self-raising flour, ground almonds, mixed spice, currants, sultanas, glace cherries, and mixed peel. Gently fold this mixture into the wet ingredients until just combined.

Step 6. Pour Batter into the Pan

Spoon the batter into the prepared cake pan, smoothing the top with a spatula.

Step 7. Bake the Fruit Cake

Bake in the preheated oven for 2-2.5 hours, or until a skewer inserted into the center comes out clean. If the top begins to brown too quickly, cover it loosely with foil.

Step 8. Cool and Glaze (Optional)

Let the cake cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely. For a shiny glaze, heat the apricot jam and water together, then brush it over the top of the cake.

Step 9. Store or Serve

Once fully cooled, the cake can be wrapped tightly in parchment paper and foil and stored in an airtight container. This cake keeps well for weeks and tastes even better after a few days.