Raspberry muffins

I've made this recipe twice over the last week now and it's been a big hit with those I've shared the end result with. :)
It's also quite simple.

2 cups Self Raising flour
3/4 cup sugar
1/2 cup softened butter
3/4 - 1 cup milk
1 teaspoon vanilla extract
1 egg
250g or thereabouts of fresh or frozen raspberries

Cream together the butter and sugar, then mix in the egg and vanilla. Using a spoon, mix in the flour (totally up to you if you want to sift it or not, I'm daring and don't bother with sifting most times) and start off using 3/4 cup of milk, mix it in and see how it goes. Should be like a slightly thick cake batter texture.. add more milk if needed. Then mix in the raspberries. Spray a 12 hole muffin pan with some form of edible oil and spoon the mixture into the pan, preferably evenly.
Bake at around 180C for 10-15 minutes or until the biggest looking muffin springs back when poked with your finger.