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A close-up of a serving of Rhubarb Dump Cake with a golden crumble topping and a dollop of whipped cream on a white plate.
Maryam

Classic Rhubarb Dump Cake

This incredibly easy and delicious Rhubarb Dump Cake features a tart, tender rhubarb base topped with a buttery, golden cake mix crumble. It's the perfect fuss-free dessert for any occasion.
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Prep Time 15 minutes
Cook Time 50 minutes
Total Time 1 hour 5 minutes
Servings: 8 servings
Course: Dessert
Cuisine: American
Calories: 380
Ingredients Equipment Method Notes

Ingredients
  

For the Rhubarb Layer
  • 6 cups Fresh rhubarb chopped into 1/2-inch pieces
  • 1 cup Granulated sugar
  • 2 tablespoons All-purpose flour
  • 1 tablespoon Lemon juice freshly squeezed
  • 1 teaspoon Vanilla extract
  • 1/2 teaspoon Ground cinnamon
For the Topping Layer
  • 1 box (15.25 oz) Yellow cake mix
  • 1 1/2 sticks Unsalted butter 12 tablespoons, melted
  • 1/2 cup Rolled oats optional, for crumble texture
  • 2 tablespoons Light brown sugar optional, for extra sweetness and crumble

Equipment

  • 9x13-inch baking dish
  • Large Mixing Bowl
  • Spoon or Spatula

Method
 

Prepare the Rhubarb Base
  1. Preheat your oven to 350°F (175°C). Lightly grease a 9x13 inch baking dish.
  2. In a large mixing bowl, combine the chopped rhubarb, granulated sugar, all-purpose flour, lemon juice, vanilla extract, and ground cinnamon. Toss gently with a spoon until the rhubarb pieces are evenly coated.
  3. Pour the rhubarb mixture into the prepared baking dish and spread it out evenly to form the base layer.
Assemble and Bake
  1. Evenly sprinkle the dry yellow cake mix over the entire rhubarb layer. Do not stir or mix it into the rhubarb.
  2. Drizzle the melted unsalted butter over the cake mix layer, trying to cover as much of the dry mix as possible. If using, sprinkle the rolled oats and light brown sugar over the butter layer for an extra crumble texture.
  3. Bake in the preheated oven for 50 to 60 minutes, or until the topping is golden brown and the rhubarb filling is bubbly and tender when gently poked with a fork.
  4. Remove from the oven and let the dump cake cool for at least 15-20 minutes before serving. This cooling time allows the filling to set properly, preventing it from being too runny.

Notes

Serve warm with a scoop of vanilla ice cream, a dollop of whipped cream, or a drizzle of custard sauce for an extra treat. Leftovers can be stored covered in the refrigerator for up to 3 days. Reheat gently in the microwave or oven if desired.