Preheat the oven to 325 degrees F (165 degrees C). Lightly grease a 9x9 inch metal baking pan and line it with parchment. Set aside.

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.

Add the eggs, egg yolks, sugar, lemon zest 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.)

Pour in the white chocolate and melted butter mixture and whisk until combined and smooth.

Fold the flour and salt into the wet ingredients with a rubber spatula just until combined.

Pour the lemon brownie batter into the prepared pan. Use a mini offset spatula to smooth the batter out.

Bake the brownies for 32-36 minutes. (Cover the pan loosely with parchment paper towards end of baking if the brownies are getting too brown.)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 pull up on the parchment paper to gently release.

Make the lemon glaze by mixing together the powdered sugar, lemon juice, pinch of salt and lemon zest in a medium bowl.

Pour the glaze over the lemon brownies and use a mini offset spatula to make an even layer of glaze. Let the glaze set, sprinkle with extra lemon zest, then cut into 16 squares and enjoy!