Strawberry Rhubarb Crisp with Buttery Oat Topping

Warm and fruity Strawberry Rhubarb Dessert is wonderful topped with a scoop of vanilla ice cream — the perfect late spring or summer treat.

Rhubarb season is here! If you love that bright, tart flavor, this Strawberry Rhubarb Dessert will be a new favorite. Made with fresh rhubarb, strawberries-like flavor from strawberry gelatin, marshmallows for extra sweetness, and a buttery cake-mix topping, this easy cobbler-style dessert is a crowd-pleaser at potlucks and family gatherings.

Serve warm with vanilla ice cream or whipped cream for a delightful contrast of hot and cold. The recipe comes together quickly and uses common pantry staples, so you can have dessert on the table with very little fuss.

What Makes This Strawberry Rhubarb Dessert So Easy

This recipe relies on a white cake mix and strawberry gelatin to add flavor and structure without complicated steps. With just a few fresh ingredients and pantry items, you get a dessert that’s part dump cake, part cobbler, and part crisp — tender, jammy fruit underneath with a crisp, buttery topping.

The combination of sweet strawberries and tart rhubarb gives a balanced, bright flavor. The marshmallows melt into the filling and add a subtle sweetness, while the cake mix and melted butter form a golden, crumbly topping.

Ingredients (for a 9×13 dish)

These are the main ingredients — full measurements are in the recipe card below.

• Fresh rhubarb: Diced, the star of the dish with its bright tartness.
• Marshmallows: Use 1 cup miniature marshmallows or about 10 regular marshmallows, quartered, to sweeten the filling.
• Sugar: Combined with the strawberry gelatin to balance rhubarb’s tartness.
• Strawberry gelatin: Adds concentrated strawberry flavor quickly.
• White cake mix: The base for the buttery crumb topping; yellow cake mix can be substituted.
• Butter: Melted and mixed into the cake mix to form a crumbly topping.
• Water: Poured over before baking to help the fruit soften and create a saucy filling.

How to Make Strawberry Rhubarb Dessert

Quick overview — full instructions and measurements follow in the recipe card below.

Prep

Preheat the oven to 350°F (175°C). Spray a 9×13-inch baking dish with nonstick cooking spray.

Fill

Spread the diced rhubarb across the bottom of the prepared baking dish. Sprinkle marshmallows evenly over the rhubarb.

Sprinkle

Combine the dry strawberry gelatin and sugar, then sprinkle that mixture over the marshmallows and rhubarb.

Mix

In a medium bowl, mix the dry cake mix with the melted butter until the mixture is crumbly.

Pour

Sprinkle the cake-mix crumble evenly over the top of the dish, then pour water over everything.

Bake

Bake at 350°F for about one hour, until the top is golden brown and the filling is bubbly.

Serve

Serve warm with vanilla ice cream or whipped cream.

Store

Store leftovers covered in the refrigerator for up to four days in an airtight container or covered baking dish.

A Quick Note About Rhubarb

Rhubarb stalks are tart and pair beautifully with sweet fruits like strawberries. When working with fresh rhubarb, discard the leaves — they contain oxalic acid and are not safe to eat. The stalks are what you use in cooking and baking.

Rhubarb: Taste and Nutrition

Rhubarb has a sour, tangy flavor similar to tart apples or citrus, which is why it’s often combined with sweeter fruits. The stalks are a good source of fiber, vitamin C, and several minerals.

Recipe Card

More Fruit Desserts

If you enjoy fruit-based desserts, try other rhubarb or strawberry favorites for variety — bundt cakes, crumble bars, and fresh fruit pies all showcase seasonal fruit beautifully.

Ready to bake this simple, comforting rhubarb cobbler? Preheat the oven and enjoy — it’s an easy recipe that consistently delights friends and family.