Step 1: Preheat your oven to 350°F (175°C). In a mixing bowl, combine the unsalted butter and 4 ounces of chopped white chocolate. Melt them together in the microwave in 30-second intervals, stirring in between, until smooth.
Step 2: Add the granulated sugar and light brown sugar to the melted butter and chocolate mixture. Stir until well combined.
Step 3: Fold in the lemon zest and salt.
Step 4: Crack in the eggs and add the lemon juice. Mix until fully combined and smooth.
Step 5: Gradually add the all-purpose flour, folding it in gently until just combined.
Step 6: Fold in the remaining 2 ounces of chopped white chocolate.
Step 7: Grease and line an 8-inch square baking pan with parchment paper. Pour the brownie batter into the prepared pan and smooth it out evenly. Bake for about 20-25 minutes, or until the edges are set.
Step 8: Allow the brownies to cool in the pan for about 10 minutes before transferring them to a wire rack. Once cooled, cut into squares and enjoy!
Notes
For best results, let your butter and eggs come to room temperature. Use fresh lemons for the best flavor, and do not over bake!