This 4-ingredient slow cooker rhubarb strawberry crumble is the kind of simple, old-fashioned dessert that has shown up on Midwestern church basement tables for generations. It starts with bright, fresh chunks of rhubarb and strawberries tossed straight into the crock with just three pantry staples—sugar, flour, and oats—then left alone to bubble into a soft, jammy fruit base with a golden, nubbly topping. It’s the sort of recipe a farm wife could pull together after supper when the rhubarb patch was overflowing and the kids had already washed the dishes, and it still works just as well today on a busy weeknight.
Serve this warm right from the slow cooker, spooned into bowls with a splash of cold cream, a scoop of vanilla ice cream, or a dollop of whipped topping. It’s lovely alongside a simple pot of coffee after Sunday dinner or with a mug of hot tea on a rainy afternoon. For a heartier spread, pair it with a light soup-and-salad supper or a grilled pork chop meal—the sweet-tart fruit makes a nice finish after something savory and simple.
4-Ingredient Slow Cooker Rhubarb Strawberry CrumbleServings: 6
Ingredients
4 cups fresh rhubarb, trimmed and cut into 1/2-inch chunks
3 cups fresh strawberries, hulled and cut into large chunks
3/4 cup granulated sugar, divided
1/2 cup all-purpose flour
1/2 cup old-fashioned rolled oats
Directions
Lightly grease the insert of a slow cooker with a bit of butter or neutral oil if you like, just enough to help with cleanup. Set the cooker to LOW but do not start it yet.
Place the fresh rhubarb chunks and strawberry chunks in the bottom of the slow cooker. The bright orange-pink and red pieces should form a colorful, even layer across the dark ceramic insert.
Sprinkle 1/2 cup of the granulated sugar evenly over the fruit. Gently toss the fruit right in the crock so every piece glistens with a light coating of sugar and its own natural juices.
In a small bowl, stir together the remaining 1/4 cup granulated sugar, the all-purpose flour, and the rolled oats until well combined. This simple mixture will form a rustic crumble topping as it cooks.
Sprinkle the flour-oat mixture evenly over the sugared fruit in the slow cooker, covering most of the surface but leaving a few colorful bits of fruit peeking through.
Cover the slow cooker with the lid. Cook on LOW for 3 1/2 to 4 hours, or until the fruit is soft and bubbling around the edges and the topping has absorbed the juices and turned tender and slightly chewy. Avoid lifting the lid during the first 2 hours so the heat stays steady.
Once cooked, turn off the slow cooker and let the crumble rest, covered, for about 15 minutes to thicken. The juices will settle into a spoonable, jammy sauce under the soft crumble topping.
Spoon the warm rhubarb strawberry crumble into bowls and serve as-is or with cream, ice cream, or whipped topping. Store any leftovers, cooled to room temperature, in a covered container in the refrigerator and enjoy within 3 to 4 days.
Variations & Tips
If your rhubarb is especially tart, you can increase the sugar by 2 to 4 tablespoons; if your strawberries are very sweet and ripe, you can reduce the sugar slightly to taste. A pinch of salt and a little ground cinnamon or nutmeg can be added to the oat-flour mixture for a more spiced, old-time flavor, though that would technically add another ingredient beyond the basic four. For a heartier, more breakfast-style crumble, swap half of the flour for additional oats or a spoonful of wheat germ. If you need this to be gluten-free, you can substitute a gluten-free all-purpose flour blend and be sure your oats are certified gluten-free. Food safety tips: Always wash the rhubarb and strawberries well under cool running water and dry them before cutting. Trim and discard rhubarb leaves completely, as they are not safe to eat; only the stalks are used. Do not leave the cooked crumble sitting on the warm setting for more than 2 hours once it’s done, and refrigerate leftovers promptly in a shallow container so they cool evenly. Reheat leftovers gently in the microwave or a low oven until steaming hot before serving.
