This is the butter cake recipe I use in all my cakes I bake for the kids Birthday’s.
125g (4oz) butter
1/2 teaspoon vanilla
1/2 cup caster sugar
1 1/2 cups self-raising flour
1/3 cup milk
Have butter at room temperature, beat butter with vanilla until light and creamy, add sugar, beat until light and fluffy; add eggs one at a time, beating well after each addition. Stir in half the sifted flour with half the milk, stir until combined. Add remaining milk and flour, stir in lightly, then beat lightly until mixture is smooth. Spread into greased tin, (I always spray my tin with baking spray and then line with baking paper). Bake in a moderate oven approx 35 mins (everyone’s ovens vary slightly so just keep an eye on the baking process). Cake is baked when a skewer/knife inserted comes out clean.
For a mixture with these quantities you can use a 20cm (8in) cake tin. Depending on the size of the cake I am making I sometimes double or triple the mixture.