Preheat the oven to 325 degrees. Lightly grease a 9x9 pan and set aside. (You can also line the pan with parchment paper for easier removal.)
Melt the butter and the white chocolate together in a double boiler over medium-low heat. Stir continuously to ensure the white chocolate gets heated evenly. Then remove from the heat.
8 oz (226 g) high quality white chocolate bars, chopped , ¾ cup (168 g) unsalted butter, chopped into small cubes
Add the eggs, egg yolks, sugar and vanilla to a large bowl and whisk together until pale and smooth. (You can also use an electric hand mixer on high speed to make it easier.)
2 eggs, 2 egg yolks, 1 ¼ cups (250 g) granulated white sugar, 1 tablespoon (15 ml) vanilla extract
Pour in the white chocolate mixture and whisk until combined and smooth.
Fold the flour and salt into the wet ingredients with a rubber spatula just until combined.
1 ¾ cups (219 g) all-purpose flour, spooned and leveled, ¾ teaspoon salt
Pour the white chocolate brownie batter into the prepared pan. Use a mini offset spatula to smooth the batter out.
Bake the brownies for 29-33 minutes. Then let the brownies cool completely in the pan on a wire rack.
Once cool, use a butter knife to loosen the edges of the brownies from the pan, and turn over to gently release. Cut into 16 squares and enjoy!