To prepare the dough, cream together the softened butter, granulated sugar, and either the lemon zest or cinnamon in a large mixing bowl. Beat the mixture on medium speed until it becomes light and fluffy, about 3 minutes. Scrape down the sides of the bowl as needed to ensure even mixing. Add the egg yolk and vanilla extract, and continue beating until the ingredients are fully incorporated.

In a separate bowl, whisk together the all-purpose flour, almond flour, and fine sea salt. Gradually add the dry ingredients to the butter mixture, mixing just until combined. Be careful not to overmix the dough, as this can result in tough cookies.

Divide the dough into two equal portions, shaping each into a disc. Wrap each disc in plastic wrap and refrigerate for about 1 hour, or until the dough is firm and easy to handle.

When ready to assemble the cookies, remove the dough from the refrigerator and allow it to soften slightly for 5 to 10 minutes. The dough should still be cold but pliable enough to roll out. On a lightly floured surface, roll out one disc of dough to a thickness of about 1/8 inch. Use a 2 1/2-inch round cookie cutter to cut out the cookies. Transfer the cut dough to a parchment-lined baking sheet. Gather any scraps, reroll, and continue cutting out cookies. If the dough becomes sticky or difficult to work with, return it to the refrigerator for about 20 minutes until it firms up.

Place the cut cookies in the refrigerator to chill for 30 minutes. While they are chilling, preheat your oven to 350°F.

As the first batch of cookies is chilling, take the second disc of dough and roll it out in the same manner. Cut out an equal number of cookies, then use a small cookie cutter or the end of a piping tip to create a small cutout in the center of each cookie. These will be the top halves of your Linzer cookies. Chill these cookies in the refrigerator for another 30 minutes.

Bake all of the cookies for 12 to 15 minutes, or until the edges just begin to turn golden. Let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.

To fill the Linzer cookies, place the cookies with the cutouts on a baking sheet and dust them generously with confectioners' sugar. Take the remaining cookies, turn them flat side up, and spread about 1/2 teaspoon of raspberry jam or lemon curd in the center. Gently press the sugar-dusted cookies on top of the filled ones, creating a sandwich with the filling visible through the cutout.