Start by gathering all your ingredients. Ensure your butter is at room temperature for easy mixing.
In a large mixing bowl, combine the softened butter and granulated sugar. Using a whisk or electric mixer, cream them together until light and fluffy, about 3-4 minutes.
Add in the egg and vanilla extract, mixing until fully incorporated.
In another bowl, whisk together the all-purpose flour, baking soda, and kosher salt. Gradually add this dry mixture into the wet ingredients, mixing until just combined.
Gently fold in the freeze-dried raspberries and chopped pistachios into the cookie dough.
Take the raspberry jam and add it to the cookie dough. Use a spatula to swirl it gently, creating a marbled effect without completely incorporating it.
Melt the white chocolate using a microwave or double boiler method. Once melted, allow it to cool slightly before drizzling it over the cookie dough.
Scoop the dough onto a parchment-lined cookie sheet, spacing each cookie about 2 inches apart. You should get about 12-15 cookies, depending on the size you prefer.
Preheat your oven to 350°F (175°C) and bake the cookies for 10-12 minutes or until the edges are lightly golden.
Once baked, remove the cookies from the oven and let them cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely. Enjoy these delightful cookies with a cup of tea or coffee!