Preheat oven to 180 degree Celsius or 160 degree Celsius fan-forced oven. Line muffin or mini-muffin pans with paper cases
Using an electric mixer, beat butter, vanilla and sugar in a small bowl until light and fluffy. Add eggs, 1 at a time, beating after each addition (mixture will separate at this stage). Transfer mixture to a large bowl. Stir in half the flour. Stir in half the milk. Repeat with remaining flour and milk until combined.
For 1/3 cup-capacity muffin pans use 2 level tablespoons of mixture. Bake for 15 to 17 minutes. Alternatively, for 1 tablespoon-capacity mini muffin pans use 1 tablespoon mixture. Bake for 10-12 minutes
Stand cakes in pans for 2 minutes. Transfer to a wire rack to cool