01 - In a large mixing bowl, beat the softened butter and powdered sugar with an electric mixer on medium speed until light and fluffy, about 2 minutes.
02 - Add the lemon zest and vanilla extract to the creamed mixture. Mix until fully combined.
03 - Sift together the all-purpose flour and salt. Gradually add dry ingredients to the butter mixture, mixing on low speed until just blended and a soft dough forms.
04 - Divide the dough in half, shape each portion into a disc, wrap tightly in plastic wrap, and refrigerate for 30 minutes.
05 - Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper.
06 - On a lightly floured surface, roll out each dough disc to 1/4-inch thickness. Using a 2-inch round cookie cutter, cut shapes from the dough and arrange half on prepared baking sheets.
07 - Using a smaller cutter, cut out the centers of the remaining cookies to form the tops. Arrange these on the baking sheets with the solid bases.
08 - Bake for 11 to 13 minutes, until edges are lightly golden. Transfer to a wire rack and allow cookies to cool completely.
09 - In a small bowl, stir fresh lemon juice into the raspberry jam until well combined.
10 - Spread about 1/2 teaspoon jam mixture onto the flat side of each solid cookie. Gently press a cookie top with a cut-out center over each, forming a sandwich.
11 - Optionally, dust the assembled cookies with powdered sugar before serving.