Ingredients
Equipment
Method
- Preheat your oven to 350°F (175°C) and lightly grease a 9×13-inch baking dish.
- In a saucepan, combine the rhubarb, sugar, corn starch, cold water, and vanilla. Set over medium heat.
- Cook the rhubarb filling for about 8 minutes, stirring occasionally, until it thickens.
- Remove the saucepan from heat once the mixture is thick and jammy.
- In a separate bowl, mix together oatmeal, flour, brown sugar, and butter using a pastry cutter or fork until the mixture forms a crumbly texture.
- Firmly press three-quarters of the crumble mixture into the prepared baking dish to form the crust.
- Spread the warm rhubarb filling evenly over the crust layer.
- If using, warm the strawberry jam slightly and drizzle it over the filling, swirling gently with a knife to create a marbled effect.
- Sprinkle the remaining crumble mixture over the top of the filling.
- Bake the bars for 30 to 35 minutes, then let them cool completely in the pan before cutting into squares.
Notes
If using frozen rhubarb, there's no need to thaw it first—simply add it straight to the saucepan and increase the cooking time slightly. The bars slice best when completely cool; cutting them warm may cause the filling to be runny and the topping to crumble. Store leftovers tightly covered in the refrigerator for up to five days. The bars travel well and are ideal for picnics or potlucks. For a gluten-free version, substitute your favorite gluten-free flour blend and use certified gluten-free oats. Serve them as is, or try with whipped cream or vanilla ice cream.