1.Preheat the oven to 350°F. Line a 8x8-inch baking pan with parchment paper, leaving some overhang for easy removal, and set aside.
2.In a large mixing bowl, whisk together the melted butter, brown sugar, and granulated sugar until well combined. Whisk in the eggs and vanilla extract until fully combined.
3.Add the flour, baking powder, and salt and mix until just combined, then fold in the white chocolate chips.
4.Scoop the batter into the prepared pan and spread it around into one even layer. Bake for 28 to 32 minutes or until the top is set and lightly browned. Remove from the oven and transfer the pan to a wire rack to cool completely before slicing into bars.