In a medium-sized bowl: combine flour, baking soda and salt. Set aside.
In a large bowl using a handheld electric mixer or using a stand mixer with the paddle attachment: cream butter, demerara sugar and granulated sugar until light and smooth (2-3 minutes on medium high speed).
Add egg and vanilla extract and continue beating until incorporated.
Switch to low speed and add flour mixture a little at a time until well blended, making sure each addition is incorporated.
Fold white chocolate chips until evenly distributed.
Scoop a heaping tablespoon of dough, gently press down a few pieces of raspberries, and shape into a ball. Freeze the cookies for about an hour.
When ready, preheat oven to 375F. Place the cookies on a baking sheet lined with parchment paper and space them about 2 inches apart. Do not flatten. Bake for 15-18 minutes or until the edges turn a light golden brown.
Cool in the pan for 5 minutes or until they firm up enough to be moved to a cooling rack to cool completely.
The total number of cookies will depend on how big or small you scoop them. Using a 1.5 tbsp cookie scoop, I get 16 cookies from this recipe.
See instructions on how to freeze your raspberries in the FAQs.
The batter will be very thick and sticky.
Optional: rotate your pan halfway through baking for a more even bake.
If you freeze the cookie dough for more than an hour, you'll need to add a few more minutes to baking time.
See post for more cookie baking tips, FAQs and step-by-step photos.