Use softened butter in a room temperature. Preheat your oven at 180℃ and shift the flour and baking powder together.

Add all sugar and beat them using hand mixer until it become fluffy and white (you can use spatula but it takes you more time)

Add the beaten egg dividing 5 times, mixing well after each addition

Add vanilla essence and flour, fold them with spatula until just combined

Spoon the mixture into cupcakes cases.