Begin by melting ½ cup of unsalted butter in a medium saucepan over medium heat. Once melted, remove from heat and pour the melted butter over 1 cup of white chocolate chips. Allow them to rest for about five minutes to soften, then whisk the mixture until it becomes smooth and creamy. Set it aside to cool for 30 minutes until slightly thickened.

In a large mixing bowl, combine the cooled butter-chocolate mixture with 1 cup of granulated sugar and whisk until thoroughly combined. Next, add in 1 teaspoon of vanilla extract and 2 room temperature eggs, mixing until the batter is smooth and glossy. Gently fold in 1 cup of all-purpose flour and a pinch of salt, being careful not to overmix. Finally, gently add in 1 to 1½ cups of fresh blueberries, ensuring they are evenly distributed throughout the batter.

Preheat your oven to 350°F (175°C) and line an 8x8 inch baking pan with parchment paper for easy removal. Pour the prepared batter into the lined pan, smoothing the top with a spatula. Bake your Blueberry Blondies in the preheated oven for 35 to 45 minutes, or until the top is golden brown and a toothpick inserted into the center comes out clean.

Once baked, remove the pan from the oven and let the blondies cool in the pan for about 10 minutes before transferring to a wire rack. Allow them to cool completely for at least 30 minutes for easier slicing. Cut them into squares, revealing the beautiful pockets of blueberries.