In a small bowl, whisk together the dry ingredients including flour, salt, and baking powder.
In a large bowl, whisk the wet ingredients including eggs, sugar, brown sugar, canola oil, and vanilla extract until smooth.
Add 1 cup of white chocolate chips to a medium microwave safe bowl with the stick of butter. Microwave at 50% power for one minute, then remove and stir. Continue to microwave at 50% power in 30 second intervals, stirring in between, until the mixture is smooth and the chocolate has melted. You can also melt the white chocolate and butter in a double boiler over low heat.
Combine the white chocolate butter mixture with the sugar mixture. Stir in the dry ingredients, then gently mix in the white chips.
Spray a 9x13 Baking dish with nonstick spray and top with a sheet of parchment paper. Pour the white chocolate brownie batter into the prepared pan and bake at 350 degrees for 40-45 minutes. Bake time will vary by oven, so keep an eye on the brownies so they don't over bake.
Place the baking dish on a wire rack and allow the brownies to cool completely for best results. Cut and serve. Makes 24 white chocolate brownies.