Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a large bowl, cream together the softened butter, white sugar, and brown sugar until light and fluffy.
Add the egg and vanilla extract. Mix until fully combined. Then cream until it becomes a lighter color.
In a separate bowl, whisk together the flour, salt, and baking soda.
Gradually add the dry ingredients to the wet mixture, mixing until just combined.
Gently fold in the white chocolate chips and frozen raspberries. (Avoid overmixing to prevent the berries from bleeding too much.)
Scoop the dough into balls (about 1.5 tbsp each) and place on the prepared baking sheet.
Bake for 10–12 minutes, or until the edges are golden and the centers are just set.
Let cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack.