Creating Raspberry Linzer Cookies is a straightforward process if you follow these detailed steps:

1. Prepare the Dough: In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.
2. Add Ingredients: Mix in the egg yolk, vanilla extract, and lemon zest. Blend until smooth.
3. Incorporate Dry Ingredients: Gradually add the flour, ground nuts, and salt to the wet mixture. Mix until just combined.
4. Chill the Dough: Form the dough into a disc, wrap in plastic wrap, and refrigerate for 30 minutes. Chilling helps the dough firm up.
5. Preheat the Oven: Preheat your oven to 350°F (175°C) while the dough chills.
6. Roll Out the Dough: On a floured surface, roll out the chilled dough to about ¼-inch thickness.
7. Cut Cookies: Using a cookie cutter, cut out shapes. For half of the cookies, create a smaller cutout in the center.
8. Arrange on Baking Sheet: Place the cookies on a parchment-lined baking sheet, spacing them an inch apart.
9. Bake: Bake in the preheated oven for 15-20 minutes, or until the edges are lightly golden.
10. Cool Cookies: Let the cookies cool on the baking sheet for 10 minutes before transferring them to a wire rack to cool completely.
11. Assemble: Spread a teaspoon of raspberry jam on the solid cookie halves. Top with the cutout cookies to create a sandwich.
12. Dust with Sugar: Finally, dust the assembled cookies with powdered sugar for a sweet finish.

By following these steps, you can effortlessly create a batch of Raspberry Linzer Cookies that are just as delightful to look at as they are to eat.