Make the dough: Cream butter, sugars, cinnamon, and vanilla with an electric mixer until light and fluffy.
Mix dry ingredients: Whisk together flour, almond flour, cornstarch, and salt in a separate bowl. Gradually stir into the butter mixture until fully combined.
Chill the dough: Divide dough into 2 discs, wrap in plastic, and refrigerate for at least 30 minutes. Preheat oven to 350°F (175°C) while the dough chills.
Roll and cut: Roll out one disc at a time to ⅛” thickness on a floured surface. Cut into 2 ½” circles, and make center cutouts on half the cookies using a small cutter.
Prepare for baking: Place cookies on parchment-lined sheets, spacing them 2” apart. Bake cutout and non-cutout cookies separately for even baking.
Bake: Bake at 350°F for 9-10 minutes until edges turn light golden. Let cookies cool completely.
Assemble cookies: Dust powdered sugar over cutout cookies. Spread jam on the flat side of the whole cookies, then top with cutout cookies to sandwich them.
Serve and enjoy! Your Linzer cookies are ready to delight!