In a bowl mix:
140 grams melted butter
1 cup caster sugar
1 teaspoon vanilla essence.
Whisk in 2 eggs. Mix well.
Add 2 cups self-raising flour
1/2 cup milk.
Then fold through 2 cups frozen blueberries.
(The mixture will be very stiff.)
Put large spoonful's into muffin cases.
Bake at 200 degrees Celsius for 15 to 20 minutes until golden.
Makes 8 large muffins or 12 small ones.