Preheat the oven to 350F. Combine both almond and all-purpose flour along with salt and whisk together.
In a stand mixer with the paddle attachment, beat together the butter and sugar until fluffy and plate yellow in color (approx. 4 mins). Then combine the egg and vanilla extract and on slow speed slowly pour in the flour mixture until just incorporated. Do not over mix.
Place the dough on a well-floured surface and create a disk shape and cover all sides with plastic wrap. Place in the fridge for 15 minutes. Place parchment paper on a baking sheet.
After 15 minutes, roll out the dough on a well floured surface about ¼ inch in thickness. With a round 1 inch cookie cutter, cut out as many rounds as possible and place them on a baking sheet. Cut out the center with a smaller cookie cutter shape of your choice for the remaining half then place into the freezer for 15 minutes. Place into the oven for only 10 minutes and place on a cooling rack to cool completely. Once cooled, place the cookies with the cut center on a plate and dust with powdered sugar and set aside. Spread some jam and hazelnut spread on the round cookies and carefully sandwich them with the top cookies.

LINZER COOKIES