Cream butter with paddle attachment. Add sugar and continue creaming. Add the egg, lemon, and vanilla and mix. Add nuts and mix. Stir together dry ingredients in a bowl and add to mixer and blend. Form into disks, wrap and chill. Roll out dough with floured rolling pin to 1/8-inch thickness on a well floured surface. Cut out disks, fluted if desired, approximately 2 inches in diameter. Cut out the centers of half the disks with a cutter in the shape of your choice. Re-roll scraps and repeat. Chill cut out dough. Bake in an oven preheated to 350 degrees F for 12 minutes or until edges turn golden then cool on a wire rack. Heat the jam and spread the solid disks with a layer of the hot jam. Glue on the lids pressing down lightly. Sprinkle with powdered sugar, then fill the holes with more jam. Let set slightly before serving.