Rhubarb Crisp is the best way to use up springtime rhubarb! This recipe is my family's favorite and you do not cook the filling ahead of time with this recipe!
Preheat your oven to 350 °F. Grease a 9x9-inch baking dish and set aside. ( 9x9 makes a much better crisp, nice and thick!)
Mix the flour, brown sugar, oats, butter, and cinnamon together in a bowl until crumbly. Press half of the oat mixture into the bottom of the 9x9 pan.
Add the sugar and cornstarch to the rhubarb, toss to coat evenly. Place on top of the oats in the bottom of the pan, making sure that the sugar is dispersed evenly throughout so it's not all in one place.
Sprinkle the remaining oat mixture over the rhubarb.
Bake in the preheated oven until crisp is lightly brown and bubbling, about 1 hour. You might have to cover the pan with tinfoil if your topping starts to brown too quickly, simply remove the last 10 minutes and make sure that the topping crisps up at the end.
Video
Notes
You might have to cover the pan with tinfoil if your topping starts to brown too quickly, simply remove the last 10 minutes and make sure that the topping crisps up at the end.
Tips and Tricks
Use salted butter in the topping!
Cut your rhubarb into 1/2 inch pieces, this is a great size that will break down nicely in the crisp.
Don't cook the rhubarb beforehand as they hold their shape slightly and it's a better texture AND presentation.