Rhubarb Crisp With Crunchy Oat Crust and Topping

The Spruce
Ratings (119)
  • Total: 70 mins
  • Prep: 15 mins
  • Cook: 55 mins
  • Yield: 8 servings
Nutritional Guidelines (per serving)
256 Calories
9g Fat
44g Carbs
1g Protein
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)

This rhubarb crisp recipe is one you'll reach for again and again. The buttery oat and cinnamon topping is simply irresistible. This rhubarb crisp is unique because it is assembled with a crumb bottom and top crust, giving you a double dose of the delicious crumble mixture. If you prefer only the topping, feel free to cut the crumble ingredients by half and omit the bottom crust, or bake it with a doubled topping. Or you might like a version made with a flour crumble topping.

Rhubarb has long been a popular choice for pies, cakes, preserves, and compotes or sauces. Its nickname is "pie plant."  All rhubarb—whether red or green—is tart, but some varieties might be less tart or a bit sweeter than others. Feel free to cut the granulated sugar back to 3/4 cup if you want to taste the tartness of the rhubarb. 

If your rhubarb stalks are more green than red, you might add a few drops of red food coloring. Or add a cup of fresh sliced strawberries to the rhubarb filling to enhance both the flavor and the color.


  • 1 cup brown sugar (firmly packed)
  • 1 cup all-purpose flour
  • 3/4 cup rolled oats (quick-cooking)
  • 1/2 cup melted butter
  • 1 teaspoon cinnamon
  • 4 cups fresh rhubarb (diced or sliced into 1-inch pieces)
  • 1 cup granulated sugar
  • 2 tablespoons cornstarch
  • 1 cup water
  • 1 teaspoon pure vanilla extract

Steps to Make It

  1. Heat the oven to 350 F (180 C/Gas 4).

  2. Butter an 8-inch square baking dish.

  3. In a mixing bowl, combine the brown sugar, flour, oats, melted butter, and cinnamon.

  4. Mix the ingredients until crumbly.

  5. Press half of the brown sugar and oat mixture into the prepared baking dish.

  6. Top with the sliced or diced rhubarb pieces.

  7. In a saucepan, combine 1 cup of granulated sugar, cornstarch, and the 1 cup of water and vanilla.

  8. Cook together, stirring, until the mixture is thickened and clear.

  9. Pour the thickened syrup mixture over the rhubarb in the baking dish.

  10. Top the rhubarb filling evenly with the remaining crumb mixture.

  11. Bake the rhubarb crisp in the preheated oven for 45 to 55 minutes, or until the topping is browned and the filling is bubbling.

Tips and Variations

  • The leaves of rhubarb contain high levels of oxalic acid. While oxalic acid is naturally present in many foods, excessive amounts can be dangerous. Always trim and discard the leaves of the plant.

  • Strawberry-Rhubarb Crisp: Add 1 cup of sliced strawberries to the rhubarb.

  • Rhubarb-Apple Crisp: Add 1 cup of thinly sliced apples to the rhubarb.

  • For subtle citrus flavor, replace the 1 cup of water with 1/2 cup of orange juice and 1/2 cup of water. Add 1 teaspoon of grated orange zest, if desired.

  • If you have only 2 or 3 cups of diced rhubarb, supplement it with diced or sliced apples.

  • Double the recipe for a 13-by-9-by-2-inch baking pan.