Make Blueberry Reduction: Blend 1½ cups of fresh blueberries until smooth. Simmer in a saucepan over medium-low heat, stirring occasionally, for 10-15 minutes until reduced to about ½ cup. Cool completely.

Prepare Oven and Pan: Preheat oven to 325°F. Line an 8x8 baking dish with parchment paper.

Combine Wet Ingredients: Melt 10 tablespoons of butter, mix in 1¼ cups of sugar, add 2 eggs, ½ teaspoon vanilla extract, and ½ teaspoon salt. Stir until smooth.

Incorporate Blueberry Reduction: Fold the cooled blueberry reduction into the wet mixture until combined.

Add Dry Ingredients: Sift 1 cup of all-purpose flour into the batter and fold gently until no dry flour remains.

Bake: Spread the batter evenly in the prepared dish and bake for 35-40 minutes or until a toothpick comes out clean.

Cool the Brownies: Allow brownies to cool completely in the pan for about 30-45 minutes.

Make the Glaze: Whisk together 1 cup powdered sugar, 2 tablespoons milk, ⅛ teaspoon vanilla extract, and a pinch of salt until smooth.

Glaze the Brownies: Spread the glaze over cooled brownies and let it set for 15-20 minutes before slicing.