Step 1

In a large bowl for a stand mixer, or using an electric whisk, cream together 1 cup of the caster sugar and 1 cup of the butter until incredibly pale and fluffy (5-10 minutes).

Step 2

Meanwhile, preheat the oven to 340F and line a 3lb loaf tin with greaseproof parchment.

Step 3

Once the butter and sugar have creamed, scrape down the sides of the bowl using a silicone spatula. Combine the flour, baking powder and bicarbonate of soda and add half the dry mix and 2 of the eggs folding to combine - do not over whisk or you’ll develop gluten resulting in a tough cake. Once combined, follow with the remaining flour and eggs, folding until fully incorporated.

Step 4

Add the buttermilk and vanilla extract, folding again until there is no marbling of colours or texture.

Step 5

Spread the mixture into the loaf tin and smooth the top of the loaf using an offset spatula. Scatter the remaining sugar over the top of the cake batter, followed by the remaining butter in cubes.

Step 6

Bake for 55-65 minutes, or until a skewer comes out clean after being inserted into the cake.

Step 7

Remove from the oven and allow to cool completely before removing from the tin, slicing and serving.