Prepare the Dough
In a mixing bowl, cream the softened butter and sugar together until light and fluffy. Add the vanilla extract and mix to combine.
Gradually add the flour and salt to the butter mixture, mixing until a soft dough forms.
Chill the Dough
Divide the dough into two equal portions. Flatten each portion into a disc, wrap in plastic wrap, and refrigerate for 30 minutes to 1 hour.
Roll and Layer
On a lightly floured surface, roll out one disc of dough into a rectangle about 1/4-inch thick. Spread half of the raspberry jam evenly over the dough, leaving a small border around the edges.
Carefully roll up the dough into a tight log, starting from the long edge. Repeat with the second disc of dough and remaining jam.
Chill Again
Wrap each dough log in plastic wrap and refrigerate for at least 2 hours, or until firm. This step is crucial for clean, even slices.
Slice and Bake
Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
Unwrap the chilled dough logs and slice into 1/4-inch thick rounds. Arrange the cookies on the prepared baking sheet, spacing them about 2 inches apart.
Bake for 12-15 minutes, or until the edges are lightly golden.
Cool and Enjoy
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.