How do I store Blueberry Blondies, and for how long?

Place them in an airtight container. At room temp they’re best within 5 days , refrigerated for 10 days , and frozen up to 3 months .

Can I use frozen blueberries?

Short answer: no . Frozen berries add too much moisture and make the texture go off. Use fresh and dry them well.

Yes. Swap in a 1:1 gluten-free flour blend and watch bake time — sometimes GF flours need a few extra minutes.

An 8×8 pan works well for thicker blondies; a 9×9 yields thinner squares. Adjust bake time accordingly.

You can, but keep quantity small. Too many add-ins weigh the batter down.

A chewy, fudgy pan of blondies studded with bursts of fresh blueberries. Perfect for picnics, potlucks, or a sunny dessert.

Scale

Place the butter in a small saucepan over medium heat and melt it completely. Put the white chocolate chips into a heatproof bowl or measuring cup.
Pour the hot butter over the white chocolate and let sit for 3–5 minutes so the chocolate softens. Whisk the mixture until smooth, then let it rest until it cools and begins to thicken (about 30 minutes).
Preheat the oven to 350°F (175°C). Line an 8×8-inch baking pan with parchment and lightly spray or grease the paper.
In a mixing bowl, combine the cooled butter–white chocolate mixture with the granulated sugar and whisk until the sugar starts to incorporate. Stir in the vanilla, then beat in the eggs until glossy.
Add the flour and salt, folding gently with a silicone spatula just until the batter comes together — don’t overwork it. Fold in the blueberries carefully so they don’t burst.
Spread the batter evenly into the prepared pan, smoothing the top.
Bake for 35–45 minutes, until the edges are golden and a toothpick inserted in the center comes out with only a few moist crumbs. (Ovens vary; check at 35 minutes.)
Cool the blondies completely in the pan on a wire rack before lifting them out and slicing into 12 or 16 squares.

Storage
- Room temperature: Keep in an airtight container for up to 5 days.
- Refrigerator: Store in a sealed container for up to 10 days.
- Freezer: Wrap slices tightly and freeze in an airtight container for up to 3 months; thaw in the fridge.
Quick tips
- Dry the berries well after washing to avoid extra moisture in the batter.
- Let the butter-chocolate cool before adding sugar and eggs — too-hot mix can make a dense, wet crumb.
- For cleaner slices, chill slightly before cutting.