Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.

In a medium bowl, whisk together the flour and salt. Set aside.

In a large bowl, beat the softened butter and powdered sugar together until light and fluffy, about 2-3 minutes.

Add the vanilla extract and egg to the butter mixture, and mix until well combined.

Gradually add the flour mixture to the wet ingredients, mixing until just combined.

Scoop tablespoon-sized portions of dough onto the prepared baking sheet, spacing them about 2 inches apart. Flatten each scoop slightly with the back of a fork.

Bake for 12-15 minutes, or until the edges are lightly golden. Remove from the oven and let cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.

While the cookies are cooling, whip the heavy cream with granulated sugar until stiff peaks form.

Once the cookies are cool, spread a layer of raspberry jam on the bottom of half of the cookies. Top with a dollop of whipped cream and place another cookie on top to create a sandwich.

Garnish with fresh raspberries if desired. Serve immediately or refrigerate until ready to serve.