Preheat the oven to 350ºF and line two baking trays with parchment paper.
Add the butter and sugar together and beat with an electric mixer until light and fluffy. You can also use a stand mixer with a paddle attachment. Be sure to scrape down the sides of the bowl to evenly blend the butter.
1/2 cup butter, softened, 1 cup sugar
Add the egg and vanilla and blend again until smooth.
1 egg, 1 teaspoon vanilla extract
Add the salt, baking powder, baking soda and flour to the bowl and blend to make a thick cookie dough.
1/2 teaspoon salt, 1/4 teaspoon baking powder, 1/4 teaspoon baking soda, 1 1/2 cups all-purpose flour
Use a rubber spatula or large spoon to stir in the frozen raspberries and white chocolate chips, if using. Only stir a few times. You don’t want the raspberries to get too smashed because they will turn the cookie dough a grayish color. One or two quick stirs is all you need!
1 cup frozen raspberries, 1 cup white chocolate chips (optional)
Scoop the cookie dough into tablespoon sized balls and place them on the prepared baking sheet trays, spacing them about 2 inches apart.
Bake the cookies in the hot oven for 12 minutes. The edges of the cookies will be a light, golden brown and the top of the cookies will be opaque and not wet looking.
Let the cookies cool on the baking tray for 5 minutes before moving to a cooling rack.