Preheat your oven to 180C and line a loaf tin with baking parchment.
In a large bowl, beat the butter, 180g of the sugar and the vanilla extract together until the mixture is light and fluffy
Beat in the eggs, one at a time, then sift the flour and baking powder over the mixture and fold in with the milk.
Spoon 1/3 of the mixture into a separate bowl. In this bowl, add the espresso shot and the extra sugar. Fold together.
In the prepared loaf tin, put the mixtures in a big spoon at a time so that the two flavours are dolloped together.
Use a long cocktail stick, skewer or a fork to swirl the two flavours together.
Bake for 55-70 minutes, until the cake shrinks slightly from the sides of the tin.
Remove the cake from the tin and leave to cool.
For the glaze, put the Werther’s Originals in a small saucepan with the double cream. Gently heat, stirring, until the toffees have melted into a smooth caramel sauce. There will be some pieces that do not melt fully, those you can discard. Cool for about 1 minute before drizzling onto your cooled cake.