Add butter and sugar into a large bowl and mix until well combined. Toss in the sugar, egg, vanilla extract, baking power and flour and beat until it becomes one large mass.
Take a teaspoon of the dough make into a small ball. Place on cooking sheet. Once this step is done, just press down in the center of the dough so that you can start adding in your Jam, or Marmalade.
Pre-heat oven and bake for 20 minutes.