Preheat your oven to 160°C (325°F) and line a baking tin with parchment paper.
In a saucepan, melt together 100g of butter, 175g of black treacle, 100g of golden syrup, and 100g of molasses sugar. Stir until well combined.
Butter, Black treacle, Golden syrup, Molasses sugar
In a separate bowl, mix together 200g of self-raising flour, 150g of medium oatmeal, 1 teaspoon of ground cinnamon, 1 teaspoon of ground cardamom, and 1 teaspoon of bicarbonate of soda.
Self-raising flour, Medium oatmeal, Ground cinnamon, Ground cardamom, Bicarbonate of soda
Combine the melted mixture with the dry mixture, stirring until all the ingredients are well incorporated.
In a separate bowl, beat 1 medium egg and mix in 150ml of milk. Add the egg and milk mixture to the batter and stir until you have a smooth, thick batter.
A medium egg, Milk
Pour the batter into the lined baking tin, spreading it evenly.
Bake for approximately 1 hour, or until a skewer inserted into the center of the cake comes out clean.
Remove the parkin from the oven and allow it to cool in the tin before cutting it into squares.