Sprinkle boxed white cake mix and these 2 ingredients over diced fresh rhubarb into a baking dish for a comforting dessert

Preheat your oven to 350°F (175°C). Lightly grease a 9×13-inch baking dish with butter or nonstick spray.

Rinse and trim the rhubarb, discarding any leaves. Dice the stalks into small pieces, about 1/2 inch thick, and pat dry with a clean towel if very wet.

Spread the diced rhubarb evenly over the bottom of the prepared baking dish, making sure it’s in a fairly even layer so it bakes uniformly.

Sprinkle the granulated sugar evenly over the rhubarb, covering as much of the surface as you can. This helps draw out the juices and sweeten the tart stalks.

Open the box of white cake mix and, using clean dry hands, evenly sprinkle the dry mix over the sugared rhubarb. Try to cover the entire surface in a light, even layer without stirring—this is what will form the crisp, cakey topping.

Slowly drizzle the melted butter over the top of the dry cake mix, aiming to moisten as much of the surface as possible. It’s fine if a few dry patches remain; they’ll still toast and crisp in the oven.

Place the baking dish on the center rack and bake for 35–45 minutes, or until the top is golden brown and crisp and the rhubarb is bubbling around the edges. If your oven runs hot, start checking at 30 minutes.

Remove from the oven and let the rhubarb crunch rest for at least 15–20 minutes. This cooling time helps the juices thicken slightly so the dessert scoops more neatly. Serve warm or at room temperature.

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