To prepare these strawberry rhubarb crumb bars, simply combine a buttery flaky crust, jammy strawberry rhubarb filling, and crumbly oat topping. The crust and crumble topping are made from the same mixture, so there’s no need to dirty an additional bowl!
- 3 cups (375g) all-purpose flour (spoon & leveled)
- 1 cup (200g) granulated sugar
- 1 teaspoon baking powder
- 1/2 teaspoon ground cinnamon (optional)
- 1/4 teaspoon salt
- 1 cup (2 sticks; 230g) unsalted butter, cold and cubed
- 1 large egg
- 2 teaspoons pure vanilla extract
- 1/4 cup (60ml) milk
- 1/3 cup (26g) old-fashioned whole rolled oats*
Strawberry Rhubarb Filling
- 2 and 1/2 cups (about 380g) chopped strawberries
- 2 and 1/2 cups (250g) sliced rhubarb (1/2 inch pieces)
- 1/2 cup (100g) granulated sugar
- 1 Tablespoon cornstarch
- 1 teaspoon orange zest
- Preheat oven to 350°F (177°C). Line the bottom and sides of a 9×13 inch baking pan with parchment paper, leaving an overhang on the sides to lift the finished bars out (makes cutting easier!). Set aside.
- Make the crumble mixture for the crust and topping: Whisk the flour, sugar, baking powder, cinnamon, and salt together in a large bowl. Add the cubed butter and using a pastry cutter, two forks, or a food processor, cut in the butter until all the flour is coated and resembles pea-sized crumbles. (See photo above for a visual.) This takes at least 5 minutes of cutting in with a pastry cutter.
- Whisk the egg, milk, and vanilla together in a small bowl. Pour over the flour/butter mixture and gently mix together until the mixture resembles moist crumbly sand. Use your hands if needed– the mixture comes together easier with your hands than with a spoon. See photo above for a visual.
- You will have about 6 cups of the crust/crumble mixture. Set 2 cups aside. Pour the remaining into the prepared pan and flatten down with your hands or a flat spatula to form an even crust. It will be a little crumbly– that’s ok. Set aside. (Oats will be used in the topping in the next step.)
- Strawberry Rhubarb Filling: Gently mix all of the filling ingredients together. Spread over the crust. Sprinkle the remaining crumble mixture all over the filling. Sprinkle the oats on over top. With the back of a large spoon or flat spatula, lightly press the topping down so it’s a bit snug on the strawberry rhubarb layer.
- Bake for about 42-50 minutes or until the top is lightly browned and a toothpick comes out *mostly* clean (with a few jammy strawberry/rhubarb specks!). Mine take about 45 minutes. Remove from the oven and allow the bars to cool completely in the pan set on a wire rack. After about 1 hour, I stick the whole pan in the refrigerator to help speed things up.
- Lift the cooled bars out using the parchment paper overhang on the sides. Cut into squares. Cover and store leftover strawberry rhubarb bars at room temperature for up to 2 days or in the refrigerator for up to 1 week.
- Make Ahead Instructions: Bars freeze well up to 3 months. Arrange in even layers in a large freezer container between sheets of parchment. Thaw overnight in the refrigerator, then bring to room temperature before serving.
- Special Tools (affiliate links): Pastry Cutter, Zester
- Don’t Have Rhubarb? Skip it and use 5 cups of chopped strawberries instead. Increase cornstarch to 1 and 1/2 Tablespoons.
- Frozen Fruit: Feel free to use frozen strawberries and/or rhubarb. Do not thaw. The bake time will be a little longer.
- Oats: Whole oats are best, but you can use quick oats if needed. I recommend this little addition because it helps evenly cover the top of the bars. If desired, replace with sliced almonds, your favorite chopped nuts, or you can skip it completely.
- Orange Zest: The orange zest is optional but it adds an extra pop of flavor to the filling. I recommend it. 1 medium orange is plenty for 1 teaspoon of zest.
- Milk: I use and recommend whole milk, but nondairy or lower fat milks will work too.
- Half Batch: Feel free to halve the recipe by halving each ingredient and baking in a lined 9-inch square baking pan. The bake time is slightly shorter. Use a toothpick to test for doneness.
Keywords: strawberry rhubarb, strawberry rhubarb pie, crumb bars