01 - In a medium mixing bowl, thoroughly whisk together the all-purpose flour, finely ground blanched almonds, ground cinnamon, and fine sea salt.
02 - In a large mixing bowl, using an electric mixer or stand mixer, cream the softened unsalted butter and 2/3 cup powdered sugar until the mixture is light and fluffy, approximately 2 to 3 minutes.
03 - Add the egg yolk, pure vanilla extract, and the optional almond extract to the creamed butter mixture. Continue to beat until all ingredients are well combined.
04 - Gradually incorporate the whisked dry ingredients into the butter mixture, mixing until a soft, cohesive dough forms.
05 - Divide the prepared dough into two equal portions. Shape each portion into a flat disc, wrap tightly in plastic film, and refrigerate for a minimum of 1 hour to firm up.
06 - Preheat your oven to 350°F. Line two large baking sheets with parchment paper for non-stick baking.
07 - On a lightly floured work surface, roll out one disc of chilled dough to an even thickness of about 1/8-inch.
08 - Using a 2-inch round or fluted cookie cutter, cut out individual cookie shapes. For the top cookies, use a smaller cookie cutter (such as a heart, star, or small circle) to create a 'window' in the center of half of the cutouts.
09 - Carefully transfer the cut cookie shapes to the prepared baking sheets, ensuring they are spaced approximately 1 inch apart. Re-roll any dough scraps as needed and cut additional cookies. Bake for 10 to 12 minutes, or until the edges begin to turn a light golden color. Allow cookies to cool on the baking sheets for 2 minutes before transferring them to a wire rack to cool completely.
10 - Once completely cooled, lightly dust the cookies with the central cutouts (the 'tops') with additional powdered sugar.
11 - Spread approximately 1 teaspoon of raspberry jam onto the flat, un-dusted side of each bottom cookie. Gently place a sugared top cookie over the jam to create a sandwich.