In a large bowl beat butter until smooth. Add sugar and beat for 2 minutes or until smooth. Then add eggs one at a time, beating well after each addition. Set aside.
In a medium sized bowl whisk together: sifted flour, hazelnut flour, cinnamon, and salt.
Add the dry ingredients to the wet in two additions and mix together until smooth.
Spilt dough into two servings and then cover with plastic wrap and refrigerate for about an hour or until batter is somewhat hard and won’t melt easily in your hands.
After an hour, preheat the oven to 350 degrees F.
On a lightly floured clean surface (I used a silicone baking mat), roll out your dough into 1/8” thickness and cut all cookies with your favorite cookie cutters; I used hearts for Valentines Day! In half of the cookies, use a smaller cookie cutter to remove the center.
Bake on an un-greased cookie sheet for 10-12 minutes until edges are golden brown. Remove from oven and let sit for 2 minutes. Using a spatula, place cookies on a wire rack to cool.
When cookies are cool, spread 1 teaspoon of your favorite jam over the bottom of the solid cookies. Using a sifter, sprinkle cutout cookies with powdered sugar and place on top of the jam covered cookie.