This Strawberry Rhubarb Blondies recipe makes 16 tender, brown-sugar blondies packed with finely chopped strawberries and tart rhubarb. The easy batter comes together in about 20 minutes, then bakes in an 8-inch square pan at 350°F (175°C) for 35–40 minutes.
Each square has buttery, chewy edges, a soft center, and bright pockets of sweet-tart fruit. Let the blondies cool for at least 1 hour before slicing so the crumb can set and the strawberry-rhubarb flavor can shine without turning the center gummy.
Jump to RecipeWhy You’ll Love This Recipe
These strawberry rhubarb blondies bring together two classic spring and early-summer flavors in a simple bar cookie. Strawberries contribute juicy sweetness, while rhubarb adds a pleasant tartness that keeps the rich brown-sugar base from tasting heavy.
The texture sits between a soft cookie and a fudgy cake. Melted butter gives the blondies a dense, chewy bite, and the extra egg yolk adds richness without making the batter complicated.
This is also a wonderfully practical recipe for using a small amount of seasonal produce. You do not need to make a separate jam or crumble topping; the fruit is tossed with sugar and cornstarch, folded directly into the batter, and finished with a few colorful pieces scattered on top.
For another fruit-forward dessert with a bright citrus note, you can also try these strawberry lemon blondies. They make a lovely companion recipe when you want to compare a tart lemon finish with the deeper flavor of rhubarb.
Ingredients You’ll Need
The ingredient list is short, but each component has an important job. Use the following quantities for one 8-inch square pan and 16 blondies.
- Butter: Melted unsalted butter creates a rich, chewy base. Let it cool slightly so it does not scramble the egg when combined.
- Brown sugar: Packed light brown sugar adds sweetness, moisture, and a gentle caramel flavor.
- Egg and egg yolk: The whole egg binds the batter, while the additional yolk contributes richness and tenderness.
- Flour, baking powder, and salt: These form the structure and balance the sweetness.
- Strawberries and rhubarb: Use 1 cup, about 150 g, of hulled finely chopped strawberries and 1 cup, about 120 g, of finely diced rhubarb.
- Sugar and cornstarch: Two tablespoons of granulated sugar sweeten the fruit, and 1 tablespoon of cornstarch or all-purpose flour helps manage its juices.
Choose firm, brightly colored rhubarb stalks and ripe but not overly soft strawberries. Pat the berries dry after washing, because surface moisture can loosen the batter and make the finished center gummy.
If you enjoy preserving the same flavor pairing, serve a spoonful of strawberry rhubarb jam alongside the blondies. Keep it as an accompaniment rather than mixing it into this formula, since the recipe is designed around fresh chopped fruit.
How to Make It Step-by-Step
Step 1: Heat the oven to 350°F (175°C), allowing it to fully preheat before the batter goes into the pan. Line an 8-inch square baking pan with parchment, leaving an overhang on two sides so the blondies can be lifted out after cooling.
Step 2: Hull and finely chop the strawberries, then dice the rhubarb into small pieces of similar size. Toss both fruits with 2 tablespoons granulated sugar and 1 tablespoon cornstarch or all-purpose flour, let them stand for about 5 minutes, and drain away excess liquid.
Step 3: Whisk the melted, slightly cooled butter with the packed light brown sugar until the mixture looks smooth and glossy. Add the large egg, egg yolk, and vanilla extract, whisking until evenly combined without incorporating excessive air.
Step 4: In a separate bowl, stir together the all-purpose flour, baking powder, and fine salt. Add this dry mixture to the butter mixture and fold gently just until no dry streaks remain; a few folds are better than vigorous stirring.
Step 5: Reserve a small amount of the drained fruit for the top, then fold the remaining strawberries and rhubarb into the batter. Stop as soon as the pieces are distributed, because overmixing can make the blondies firm instead of tender.
Step 6: Scrape the batter into the parchment-lined pan and spread it into an even layer. Scatter the reserved fruit over the surface, pressing it in very lightly so it stays visible and creates colorful fruit pockets as the blondies bake.
Step 7: Bake for 35–40 minutes, watching for lightly browned, set edges and a center that is just set. Test the middle with a toothpick; moist crumbs are right, while wet batter means it needs more time.
Step 8: Place the pan on a cooling rack and let the blondies cool completely for at least 1 hour. Lift them out using the parchment overhang, and chill briefly before cutting if you want exceptionally tidy squares.
Pro Tips for Perfect Blondies
Fruit moisture is the main detail to manage. Strawberries release juice quickly after they are cut, so prepare the fruit close to mixing time, keep the pieces small, and drain the mixture before it joins the batter.
Do not wait for a completely clean toothpick. A clean tester often means the blondies have been baked too long, especially in an 8-inch pan; moist crumbs indicate a soft center that will firm as it cools.
For the most even texture, measure flour carefully and avoid packing it into the measuring cup. If using volume measurements, spoon the flour into the cup and level it rather than scooping directly from the bag.
The parchment overhang is more than a convenience. It prevents the fruit-studded edges from sticking and makes it possible to transfer the entire slab to a cutting board without damaging the delicate center.
Especially juicy fruit can be cooked before adding it. Simmer the strawberries and rhubarb with the sugar for 5–8 minutes, stir in the cornstarch, and cool the thickened mixture completely before swirling it through the batter instead of folding in raw fruit.
Serving Suggestions
Serve these blondies at room temperature for the softest, most fragrant texture. Their brown-sugar flavor is especially good with coffee, black tea, or a cold glass of milk.
For a dessert plate, add a scoop of vanilla ice cream or a small spoonful of lightly sweetened whipped cream. The cool creaminess contrasts with the tart fruit and makes the blondies feel suited to a dinner party without requiring a complicated finish.
Dusting with powdered sugar is optional, but keep the garnish light so it does not hide the strawberries and rhubarb. A few thin strawberry slices placed beside each serving are enough to make the fruit flavor clear.
If you are planning a larger casual spread, these bars can sit beside a crisp fruit dessert such as our easy strawberry crisp. The blondies offer a chewy bite, while the crisp brings a warm, spoonable contrast.
Storage and Slicing
Cool the blondies completely before covering them. Store them in an airtight container at room temperature for up to 2 days, or refrigerate them for a firmer texture and longer keeping quality.
Place parchment between layers if stacking the squares. Refrigerated blondies slice very cleanly, while a short rest at room temperature before serving brings back some of their softer chew.
For the sharpest edges, use a large chef’s knife and wipe the blade between cuts. Divide the cooled slab into four strips in each direction to make 16 even blondies.
These bars are best enjoyed as a sweet finish, but the same seasonal menu can include savory favorites too. Consider pairing them with grilled Hawaiian chicken sandwiches for a relaxed summer meal, or serve easy air fryer meatballs as a party appetizer before dessert.
Strawberry Rhubarb Blondies
Ingredients
Method
- Heat the oven to 350°F (175°C). Line an 8-inch square baking pan with parchment paper, leaving enough overhang on two sides to lift out the cooled blondies.
- Toss the finely chopped strawberries and diced rhubarb with the granulated sugar and cornstarch. Let the mixture stand for about 5 minutes, then drain off excess liquid.
- Whisk the melted, slightly cooled butter and packed brown sugar together until combined. Add the egg, egg yolk, and vanilla, then whisk until smooth.
- In a separate bowl, stir together the flour, baking powder, and salt. Fold the dry mixture into the butter mixture just until no dry streaks remain.
- Fold most of the prepared strawberry-rhubarb mixture into the batter, reserving a small amount for the top. Spread the batter in the lined pan and scatter the reserved fruit over the surface.
- Bake for 35–40 minutes, until the edges are set and lightly browned and the center is just set. A toothpick should come out with moist crumbs, not wet batter.
- Cool completely in the pan for at least 1 hour before lifting and cutting. Chill briefly if you want especially clean, neat slices.
Notes
Final Thoughts
This Strawberry Rhubarb Blondies recipe is a dependable way to turn fresh seasonal fruit into a memorable bake. The buttery brown-sugar base is simple enough for a weeknight, yet the jewel-like fruit and soft center make every square feel special.
Remember the three details that matter most: drain excess fruit liquid, fold gently, and remove the pan when the toothpick shows moist crumbs rather than wet batter. Cooling for at least 1 hour completes the texture and makes slicing much easier.
Make a batch for picnics, bake sales, afternoon coffee, or a family dessert. Once you taste the combination of chewy blondie, sweet strawberry, and tangy rhubarb, this colorful bar recipe is likely to become a favorite whenever the fruit is in season.