Begin by melting ½ cup of unsalted butter in a saucepan over medium heat until it becomes foamy and bubbly. Remove from heat and add 1 cup of white chocolate chips, letting them sit for about 5 minutes. Whisk until smooth, then set aside to cool for about 30 minutes.

In a mixing bowl, combine the cooled butter and white chocolate mixture with 1 cup of granulated sugar, whisking until fully blended. Add in 2 large eggs and 1 teaspoon of vanilla extract, mixing until well incorporated.

Gently fold in 1 cup of all-purpose flour and a pinch of salt, stirring just until combined. Fold in 1 cup of fresh blueberries carefully to keep them intact.

Preheat your oven to 350°F (175°C) and line an 8x8-inch baking pan with parchment paper. Pour the batter into the prepared pan, smoothing the top. Bake for 35-45 minutes or until the top is golden brown.

Allow the blondies to cool in the pan for 10 minutes before transferring them to a wire rack. Let them cool completely for at least 30 minutes, then slice into 12-16 squares.