Strawberry Rhubarb Crisp With Buttery Oat Topping

Strawberry rhubarb crisp pairs tart rhubarb with sweet strawberries under a buttery oat topping that bakes golden and crunchy. It serves 8, takes about 55 minutes including baking, and works with fresh rhubarb while it is in season.

Ingredients

For the Fruit Filling

• 4 cups chopped rhubarb
• 3 cups sliced strawberries
• 1/2 cup granulated sugar
• 1/4 cup light brown sugar
• 3 tablespoons cornstarch
• 1 teaspoon vanilla extract
• 1 tablespoon lemon juice
• Pinch of salt

For the Oat Crisp Topping

• 1 cup old-fashioned oats
• 3/4 cup all-purpose flour
• 3/4 cup light brown sugar
• 1 teaspoon cinnamon
• 1/2 teaspoon salt
• 1/2 cup cold unsalted butter, cubed

Fresh rhubarb works best here because it keeps a little texture after baking. If using frozen strawberries, thaw and drain them first so the filling does not turn watery.

Assembling and Baking the Crisp

1. Preheat the oven to 375°F and lightly grease a 9-inch baking dish. In a large bowl, toss the rhubarb, strawberries, sugars, cornstarch, vanilla, lemon juice, and salt until the fruit looks evenly coated and glossy.

2. Spread the fruit mixture into the baking dish. The filling may seem slightly dry at first, but the strawberries and rhubarb release plenty of juice as they bake.

3. In another bowl, mix the oats, flour, brown sugar, cinnamon, and salt. Cut in the cold butter with a pastry cutter or your fingertips until the mixture forms chunky crumbs with pea-sized bits of butter throughout.

4. Sprinkle the oat topping evenly over the fruit. Leave some larger clumps intact because those pieces bake into the crispiest topping.

5. Bake for 35 to 45 minutes, until the fruit filling is bubbling hard around the edges and the topping turns deep golden brown. One thing to watch for is pale topping in the center — if needed, bake an extra 5 minutes for more color and crunch.

6. Let the strawberry rhubarb crisp cool for at least 15 minutes before serving. The filling thickens as it cools, making it easier to scoop.

Why Rhubarb and Strawberry Work Together

Strawberries soften the sharp tartness of rhubarb without hiding it, and a small amount of cornstarch thickens the juices so the filling stays spoonable instead of soupy.

The topping uses cold butter rather than melted butter, which makes crisp clusters instead of a sandy crumble. Old-fashioned oats give better texture than quick oats.

Fixing a Loose Filling or a Soft Topping

• If the filling is loose after baking, let the crisp rest another 10 to 15 minutes; it thickens as it cools.
• If the topping is not crunchy, the butter was probably too soft or the crisp was underbaked. The top should look deeply golden and dry.
• Set the baking dish on a sheet pan to catch bubbling juices.
• If the topping browns too fast, tent the dish loosely with foil for the last 10 minutes.
• For extra texture, add 1/2 cup chopped pecans or walnuts to the topping.

Frozen Fruit and Thickener Swaps

• Frozen rhubarb or strawberries: Thaw and drain first. Both release extra liquid, and skipping this makes the filling watery. Fresh rhubarb holds more texture.
• Flour or tapioca starch for cornstarch: Both thicken the filling; expect tapioca to give a slightly glossier finish.

Serving, Making Ahead and Storing

Serve warm with vanilla ice cream or lightly sweetened whipped cream to balance the tart fruit, or spoon plain Greek yogurt over it for brunch. If you want more rhubarb desserts, try the rhubarb crumble with oat topping, the rhubarb dump cake or a strawberry rhubarb pie.

You can assemble the dish a few hours ahead and refrigerate it before baking; add about 5 minutes to the baking time if it goes in cold. Refrigerate leftovers within 2 hours and eat within 3 to 4 days. The baked crisp freezes for up to 2 months: cool fully, wrap tightly, and reheat in a 350°F oven until the topping crisps and the filling is hot.

FAQ

Can I use frozen rhubarb?

Yes, but thaw and drain it first so the filling does not turn watery.

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