You will need:
125g butter very well softened (i just blitz it in the microwave for 30 secs)
1 teaspoon vanilla extract
1 cup caster sugar
1 1/2 cups plain flour
1/2 teaspoon baking powder
1/4 teaspoon bicarb soda (baking soda)
1/2 cup milk
Preheat your oven to 150oC
Grease and flour your desired tin.
Simply throw everything in to a big bowl and mix till just combined
Pour in to the tin.
Bake for approx 40 minutes or until top is lightly golden brown and springs back to the touch.
Allow to cool for five mins in it's tin then turn on to a wire rack.
When cool, dust with icing sugar and enjoy