Go Back

Homemade Rhubarb Crunch

Rhubarb crunch with a sweet, jammy rhubarb filling and an extra-thick oat topping that turns deep golden and crispy in the oven. This classic spring dessert bakes up like a rustic crumble bar—sliceable and spoon-tastic.
Print Recipe Pin Recipe
Prep Time 15 minutes
Cook Time 45 minutes
cooling 10 minutes
Total Time 1 hour 10 minutes
Servings: 8 servings
Course: Dessert
Cuisine: American
Ingredients Equipment Method Notes

Ingredients
  

rhubarb filling
  • 5 cup fresh rhubarb
  • 1.25 cup sugar
  • 0.25 cup all-purpose flour
  • 1 tsp vanilla extract
oat topping
  • 1.5 cup old-fashioned oats
  • 1 cup all-purpose flour
  • 1 cup brown sugar
  • 0.75 cup butter melted
  • 1 tsp cinnamon
  • 0.5 tsp salt

Equipment

  • 1 sheet pan

Method
 

Prep and bake
  1. Preheat oven to 350°F and butter a 9x13-inch baking dish so the rhubarb doesn’t stick and the topping can crisp evenly.
  2. Combine fresh rhubarb, sugar, all-purpose flour, and vanilla extract, then spread the mixture evenly in the prepared dish for a thick, suspended filling.
  3. Mix old-fashioned oats, all-purpose flour, brown sugar, melted butter, cinnamon, and salt until well combined so the topping holds together in clumps.
  4. Spread the topping thickly and evenly over the rhubarb for a full crunch layer that won’t thin out during baking.
  5. Bake at 350°F for 40-45 minutes until the topping is deep golden and crispy, with the filling bubbling at the edges.
Cool and serve
  1. Cool for 10 minutes so the filling sets slightly and slices cleanly before serving.
  2. Serve warm (optional: with vanilla ice cream) so the crispy topping meets the warm rhubarb filling.

Notes

To keep the crunch extra crisp, let the baked dish rest the full 10 minutes before cutting. Refrigerate leftovers in an airtight container up to 4 days; reheat slices in a 325°F oven until warmed. Freezing is not recommended because the oat topping softens after thawing. For a dairy-free swap, use plant-based butter in the topping.