Mocha Choca Bailey's Muffins

I finally got round to baking birthday muffins for work this morning, and before breakfast at that! Quite a tasty combination, even though I didn't know what day it was by the time I arrived in work - but I put that down to the 12 hours sleep I'd had just prior to baking - what a strange week this has been!!

Anyway:

In a large bowl mix together:
220g caster sugar
375g self-raising flour

In a small bowl mix together:
90g melted salted butter
half cup sour cream
quarter cup Bailey's
a desert spoon of coffee granules diluted in the minimum amount of boiling water
2 large eggs

Mix the wet into the dry

Stir in:
100g white chocolate chips

Divide the mixture between 12 muffin cases
Bake on Gas 5/6 for 20-25 minutes
Leave in the tin for a few minutes before removing onto a wire rack to cool