In the bowl of a stand mixer, combine the granulated sugar and citrus zest. Add the softened butter and beat until the mixture is fluffy and light.

Next, add the egg yolk and vanilla extract to the bowl. Mix until everything is well combined.

In a separate bowl, whisk together the all-purpose flour, almond flour, salt, and cinnamon. Gradually add these dry ingredients to the butter mixture and mix until just combined. Be careful not to overmix!

Scrape the dough onto a piece of plastic wrap, shape it into a disc, and wrap it tightly. Refrigerate for at least 1 hour.

Once chilled, roll out the dough on a floured surface to about 1/4 inch thick.

Use a cookie cutter to cut out the cookies. For half of the cookies, use a Linzer cutter to create a heart in the center.

Place all cookies on a parchment-lined baking sheet. Chill them in the fridge while you preheat your oven to 350°F (175°C).

Bake the cookies for 10-12 minutes, or until the edges are slightly browned. Once done, cool them on a wire rack.

After the cookies have cooled, sift powdered sugar over the cookie tops with cutouts. Spread a layer of strawberry jam on the whole cookies and top with the sugar-dusted ones to create delightful sandwiches.