Preheat oven to 375°
Cream the granulated sugar and salted butter together until light and fluffy.
Add the egg and lemon zest to the sugar and butter mixture. Whip for 1-2 mins on medium speed.
Sift the bread flour and cinnamon together then add the ground hazelnuts to the bread flour and whisk gently to incorporate.
Add the flour mixture to the mixing bowl and mix until incorporated.
Press the dough together in the mixing bowl then put it on the dusted countertop.
With a rolling pin, roll the dough out to a ¼ inch thick. Roll from the outside edges into the middle. I know that sounds counterproductive but you will get a smoother result with less cracking.
Use the circle cookie cutter to cut out as many as the dough will allow (about: 24). Then use the heart cookie cutter to cut the centers out of half of the circles.
Transfer the cookies with a spatula to separate parchment lined cookie sheets. Take your time, you don’t want to distort the circle or the heart. The heart clout cookies will take less time to bake.
Bake for heart cutouts for 5 minutes. Bake the circle cookies for 7 minutes.
Remove from the oven and allow to cool for about 5-10 mins on the cookie sheet. After the cookies have cooled slightly, transfer the cookies to a wire rack to finish cooling.
Once the cookies are completely cool, spread a small amount of jam on the whole circles and set aside.
Dust the tops of the cutout cookies with powdered sugar. Try not to touch the sugar.
With an offset spatula or butter knife lift the dusted cutout cookie and place it on top of the cookie with jam.