I've baked dozens of cookie recipes over the years, but this 1 recipe is most requested year over year

Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a large bowl, cream together the softened butter and powdered sugar until light and fluffy.
Mix in the vanilla extract.
Gradually add the flour to the butter mixture, blending until the dough comes together.
Roll the dough into 1-inch balls and place them on the prepared baking sheet about 2 inches apart.
Using your thumb, make an indentation in the center of each cookie.
Fill each indentation with a small amount of raspberry jam or preserves.
Bake the cookies for 12-15 minutes or until the edges are lightly golden.
Remove the cookies from the oven and let them cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.