In a mixing bowl, combine unsalted butter and granulated sugar. Cream together for about 3 minutes until light and fluffy.

Add egg and vanilla extract. Mix on low speed until fully incorporated and mixture is smooth, about 1–2 minutes.

In a separate bowl, whisk together all-purpose flour, powdered sugar, and salt. Gradually add dry mixture to wet ingredients, stirring until just combined.

For the raspberry swirl, gently warm jam in the microwave for 15-20 seconds or blend fresh raspberries into a smooth puree and strain.

Turn out cookie dough on a floured surface and roll out to 1/4 inch thick. Spread raspberry swirl over the dough.

Gently roll the dough into a log shape, wrap in plastic wrap, and refrigerate for at least 1 hour.

Preheat oven to 350°F (175°C). Slice chilled dough into 1/4 inch rounds and place on a parchment-lined baking sheet. Bake for 10-12 minutes until edges are lightly golden.

Allow cookies to cool on the baking sheet for about 5 minutes before transferring to a wire rack.