Mix butter, sugar and the yolks together with a fork. Leaving the butter out of the fridge for about 30 minutes before starting will help on this step.
Add the baking powder and half of the flour and go on mixing it with a fork
At some point the dough will start getting a little harder and you will need to start working it with your hands for 1 minute.
Keep adding the flour until the dough is no longer sticky
Grease a springform pan (the ones that open on the side) with butter and flour.
Get 3/4 of the dough and spread it on the baking dish leaving a 1/2 inch high border
Spread the marmelade on top fo the dough
Use the rest of the dough to add decorations on top of the marmalade.
Bake for 40 min or until the borders begin to golden at 180?C (350F)