Thermomix: Add flour and sugar to mixing bowl and mix 5 sec / speed 5. Add butter pieces and mix 5 sec / speed 5. Add egg and mix 10 sec / speed 5.

If you do not have a Thermomix, add the flour and sugar to the bowl of a food processor. Pulse 2-3 times to blend. Add butter pieces and process until a crumbly consistency. Add egg and process until dough forms.

Remove dough from mixing bowl and shape into a disc. Cover tightly with plastic wrap and refrigerate for at least 30 minutes.

Preheat oven to 350 degrees F. Line a baking sheet with parchment paper and set aside.

Remove dough from refrigerator and roll out on a floured surface to about 1/8 inch thick. Use a heart shaped cookie cutter, about 3 inches in diameter to cut out 8 cookies. Using a smaller cookie cutter (about 1 1/2-inch) cut out a heart in the center of 4 of the cookies (this will be the top cookie). Transfer cut out cookies shapes to prepared baking sheet and bake 15-18 minutes.

Remove from oven and cool completely.

To assemble the cookies, spread jam onto the flat sides of the bottom cookies (without the hole). Dust the tops with powdered sugar and place on top of the jam.