Preheat your oven to 350°F (175°C).

In a small bowl, combine the flour, baking powder, baking soda, and salt. Mix until evenly blended.

In a separate large bowl, beat the butter, granulated sugar, and brown sugar together on medium-high speed until the mixture becomes light and fluffy.

Add the egg and vanilla extract, mixing until fully combined.

Reduce the mixer speed and gradually add the flour mixture. Mix until the dough is thick and fully incorporated.

Stir in the white chocolate chips using a spatula.

Gently fold in the frozen raspberries. It’s normal if some of them break apart while mixing.

Roll the dough into 1-inch balls and place them about 2 inches apart on a baking sheet lined with parchment paper or a silicone baking mat. Flatten each dough ball slightly.

Bake for 10–12 minutes, or until the bottoms of the cookies are lightly golden.

Allow the cookies to cool for about 5 minutes on the baking sheet, then transfer them to a cooling rack to cool completely.