Preheat the oven to 180 degree celcius.

Grease a baking pan with a little bit of unsalted butter.

In a bowl, mix the unsalted butter and sugar until light, fluffy and airy. Add in one egg at a time and beating well until the mixture is thoroughly combined.

In another bowl, whisk the all purpose flour with the baking powder.

Pour the butter mixture into the flour mixture and fold the mixture until thoroughly combined.

Pour the mixture into the baking pan and bake it for about 15-20 minutes or until an inserted toothpick comes out clean.

Let it cool, serve and enjoy!