Preheat your oven to 300°F / 150°C. Thoroughly grease and line a large or Pullman loaf tin with parchment paper, leaving some overhang on the sides for easy removal; binder clips can help keep the paper in place.

In a medium saucepan over medium heat, combine the treacle and butter, stirring occasionally until fully melted without allowing the mixture to boil. Once melted, take off the heat and stir in the milk to cool slightly. Allow the mixture to rest for 10 minutes to avoid cooking the eggs.

While the mixture is cooling, sift together the flour, sugar, baking powder, baking soda, salt, ground ginger, cinnamon, mixed spice, nutmeg, and cardamom into a large bowl. Stir to evenly distribute the dry ingredients.

When the treacle mixture is tepid, whisk in the eggs until smooth and fully incorporated.

Pour the wet mixture into the bowl of dry ingredients and whisk vigorously until the batter is smooth and no lumps remain.

Transfer the mixture to the prepared loaf pan and spread evenly.

Bake for 1 hour and 20 minutes, or until a skewer inserted into the center comes out clean — ensure the skewer reaches the base of the pan.

Allow the loaf to cool in the tin before transferring it to a wire rack to cool completely.

Serve generously sliced and slathered with butter.

For storage, wrap the loaf well in plastic wrap or place in an airtight container at room temperature for up to one week.