Strawberry Rhubarb Bars Recipe with Oat Crust

We love these Strawberry Rhubarb Bars—a bright, slightly sweet summer dessert made with simple, real ingredients. They’re perfect for backyard barbecues, potlucks, or holiday gatherings and travel easily in a pan for picnics and lake days. The combination of tart rhubarb and sweet strawberries baked into an oat-studded crumb is a true seasonal favorite.

The Best Strawberry Rhubarb Bars

If you love classic strawberry rhubarb pie or a fruit crisp, these bars deliver the same nostalgic flavor in an easier, more portable format. Bars are ideal when you need to feed a crowd or want something you can cut into portions without extra effort. Serve them warm with a scoop of vanilla ice cream or let them cool completely for neat squares that travel well. The crumbly oat topping and buttery crust balance the bright fruit filling, making these bars a summer staple.

What You Will Need

• Light brown sugar & cane sugar – a blend that gives the right level of sweetness and caramel notes.
• All-purpose flour & old-fashioned oats – the base for the crust and topping. Swap in 1-to-1 gluten-free flour and certified gluten-free oats to make them gluten-free.
• Ground flax – added for a small nutritional boost and texture.
• Kosher salt – a pinch to enhance flavor.
• Egg – binds the crust together.
• Vanilla extract – adds depth to the crust and filling.
• Salted butter – makes the crust and crumb golden; use non-dairy butter to make the recipe dairy-free.
• Fresh strawberries & fresh rhubarb – best in season, but you can use frozen if thawed and patted dry.
• Lemon juice & orange zest – a touch of acidity and citrus brightens the fruit filling.
• Cornstarch – thickens the filling so it isn’t runny.
• Ground nutmeg – a small pinch adds warm spice.
• Honey – boosts the fruit’s natural sweetness.

How To Make Strawberry Rhubarb Bars

This recipe is straightforward. Start by combining the dry ingredients for the crust in a large bowl, then mix in the wet ingredients and cut the butter into the flour to form a crumbly dough.

Whisk the egg with vanilla and stir into the flour mixture, then add cubed butter and use a fork or pastry cutter to incorporate it until the mixture resembles coarse crumbs. Press slightly more than half of this mixture firmly into the bottom of a parchment-lined 9 x 13-inch baking pan to form the crust. Reserve the remaining crumb mixture for the topping.

Prepare the filling by chopping the strawberries and slicing the rhubarb, then tossing them with sugar, cornstarch, lemon juice, honey, orange zest, vanilla, and a pinch of nutmeg until well coated. Pour the fruit mixture evenly over the pressed crust and spread it to the edges.

Mix three tablespoons of brown sugar into the reserved crust mixture to create the crumb topping, then sprinkle it evenly over the fruit layer. Bake on the middle rack at 375°F (190°C) for 38–40 minutes or until the filling is bubbly and the top is golden brown.

Remove from the oven and allow the bars to cool completely in the pan before cutting into squares so the filling sets and the pieces hold together cleanly.

Best Way To Enjoy Strawberry Rhubarb Bars

These bars are delicious on their own, but serving them slightly warm with vanilla ice cream or a dollop of Greek yogurt elevates them. The contrast between warm fruit and cool cream creates a delightful texture and flavor balance. They also make a convenient snack for outdoor gatherings—cut into squares and store in an airtight container for transport.

Recipe FAQ

• Frozen fruit: Fresh fruit gives the best texture, but you can use frozen if you thaw and pat it dry first to remove excess moisture.
• Cooling: Let the pan cool completely before slicing. Cooling helps the filling set so bars hold together when cut.
• Storage: Keep covered at room temperature for a day or two, then refrigerate. Stored in the refrigerator, the bars will keep for up to 5 days.

Strawberry Rhubarb Bars Recipe

Ingredients

Crust / Topping Mix

• 2 ¾ cups all-purpose flour (or 1-to-1 gluten-free flour)
• ½ cup + 3 tablespoons brown sugar
• ½ cup organic cane sugar (or granulated sugar)
• ¼ cup rolled oats (use certified gluten-free if needed)
• 1 tablespoon ground flax
• Pinch kosher salt
• 1 egg
• 1 teaspoon vanilla extract
• 1 cup salted butter, room temperature and cubed (or dairy-free alternative)

Filling

• 3 cups strawberries, stems removed and quartered
• 2 ½ cups rhubarb, cut into ½-inch slices
• ⅓ cup organic cane sugar (or granulated sugar)
• 1 tablespoon cornstarch
• 1 tablespoon lemon juice
• 1 tablespoon honey
• 1 teaspoon orange zest
• 1 teaspoon vanilla extract
• ¼ teaspoon ground nutmeg

Instructions

1. Prep: Preheat oven to 375°F. Line a 9 x 13-inch pan with parchment and spray the bottom lightly with non-stick spray.
2. Dry ingredients: In a large bowl whisk together flour, ½ cup brown sugar, ½ cup cane sugar, oats, ground flax, and a pinch of kosher salt.
3. Wet ingredients: In a small bowl whisk the egg and 1 teaspoon vanilla. Add to the flour mixture, then add the cubed butter and cut it in with a fork until the mixture is crumbly.
4. Make crust: Press just over half of the crumb mixture firmly into the prepared pan to form an even crust. Reserve the rest for the topping.
5. Filling: In a medium bowl combine strawberries, rhubarb, ⅓ cup sugar, cornstarch, lemon juice, honey, orange zest, vanilla, and nutmeg. Stir until the fruit is evenly coated, then spread the filling over the crust.
6. Topping: Stir 3 tablespoons brown sugar into the reserved crumb mixture, then crumble it evenly over the fruit.
7. Bake: Bake on the middle rack for 38–40 minutes, until the top is golden and the filling is bubbling.
8. Serve: Cool completely in the pan before cutting into squares. Serve warm with vanilla ice cream or Greek yogurt if desired.

Notes

• Brown sugar swap: Coconut sugar can replace brown sugar for a slightly less sweet result.
• Gluten-free: Use 1-to-1 gluten-free flour and certified gluten-free oats to make this gluten-free.
• Dairy-free: Use a plant-based butter to make the bars dairy-free.
• Storage: Store covered in the refrigerator for up to 5 days. For short-term transport, keep covered at room temperature for up to 48 hours and then refrigerate.

Nutrition (per serving)

Calories: 185 kcal • Carbohydrates: 26 g • Protein: 2 g • Fat: 8 g • Sugar: 13 g • Fiber: 1 g