Ingredients
Equipment
Method
Prep the oven and pan
- Preheat oven to 350°F (175°C). Set a rack in the middle so the blondies bake evenly.
- Line a 9×13-inch baking pan with parchment paper. Leave overhang to lift out and slice neatly.
Mix the blondie batter
- Whisk melted butter and brown sugar in a large bowl until smooth. Stop when the mixture looks glossy and fully combined.
- Add eggs and vanilla extract, then mix well. Whisk until the batter looks uniform and slightly thickened.
- Stir in all-purpose flour, baking powder, and salt until combined. Mix just until no dry streaks remain for a tender center.
Fold in mix-ins and bake
- Toss fresh blueberries with 1 tablespoon flour until coated. This helps prevent sinking and reduces streaky pockets.
- Fold white chocolate chips and the coated blueberries into the batter. Distribute gently so berries stay intact.
- Spread batter evenly into the prepared pan. Smooth the top to encourage even baking.
- Bake for 30–35 minutes at 350°F (175°C). Bake until lightly golden and a toothpick comes out mostly clean with a few moist crumbs.
Cool and slice
- Cool the blondies completely before slicing into squares. Letting them set prevents crumbling and keeps chewy edges.
Serve
- Serve the blueberry white chocolate blondies as squares. Cut clean portions with parchment lift for easy handling.
Notes
For the best chewy edges, avoid overmixing after adding the dry ingredients and don’t overbake—pull at lightly golden with moist crumbs. Store covered at room temperature for up to 3 days or refrigerate for up to 5 days. Freeze baked squares for up to 2 months (thaw overnight in the fridge). For a lower-sugar option, use a reduced-sugar light brown sugar substitute in the same amount.