Preheat the oven to 325 degrees F. Prepare a 9 x 13 baking dish with foil or spay with non-stick spray.

Cream together the butter and sugar with a paddle attachment until well blended and fluffy. Add in egg yolks and vanilla. Beat in well. Incorporate in the flour.

Spread half of the dough mixture into the pan and press down. Spread jam over dough. I used about 8 oz of jam, but I think I should have used more. Take a handful of remaining dough and press in your palms. Lay the remaining dough over the jam and continue to add more of the dough to cover all of the jam.

Bake for 1 hour.

Cool completely.

Cut into squares and sprinkle with powdered sugar.