Preheat oven to 350 degrees Line an 8 x 8 inch pan with parchment paper, leaving an overhang on two opposite sides. Spray lightly with nonstick spray.

In a small bowl, combine flour, baking powder and salt; set aside.

In a medium saucepan, melt butter over low heat. Stir in brown sugar just until moistened. Remove from heat and let cool slightly. Whisk in egg and vanilla. Stir in flour mixture just until combined. Stir in white chocolate chips.

Pour batter into prepared pan, smoothing out and spreading evenly. Scatter strawberries over batter.

Bake until set in center, about 25-30 minutes. Cool completely in pan on wire rack. Refrigerate for at least 1 hour before cutting. Lift out of pan by parchment paper handles and cut into 12 bars. Serve.