Preheat oven to 350°F (175°C). Line baking sheets with parchment paper.

In a medium bowl, whisk together flour, baking powder, baking soda, and salt.

In another bowl, cream butter and brown sugar until light and fluffy. Add egg and vanilla extract, mixing well.

Gradually mix in dry ingredients until just combined.

Fold in white chocolate chunks and mashed raspberries.

Drop batter onto prepared baking sheets, spacing 2 inches apart. Flatten slightly.

Bake 12–15 minutes until lightly golden around edges. Cool on baking sheet 5 minutes, then transfer to wire rack.