This easy baked watermelon dessert is the kind of playful shortcut recipe that makes busy weeknights and summer gatherings feel a little more fun. Using dry strawberry cake mix, juicy watermelon, melted butter, and a simple topping ingredient, it bakes into a soft, jammy, cobbler-style treat with a sweet berry flavor that fits right in for National Watermelon Day. It is a great option when you want something homemade without pulling out a long list of ingredients or spending all evening in the kitchen.

Serve this dessert warm with vanilla ice cream or a dollop of whipped cream to balance the sweet fruit and cake topping. It also pairs nicely with fresh strawberries, a spoonful of vanilla yogurt for brunch, or even a cup of coffee if you are serving it as a casual after-dinner treat on the patio.

4-Ingredient Oven Baked Watermelon Strawberry Cake Dessert

Servings: 8

Baked watermelon strawberry cake dessert in a glass casserole dish
Baked watermelon strawberry cake dessert in a glass casserole dish

Ingredients

4 cups seedless watermelon, cut into small cubes

1 box dry strawberry cake mix, unbaked
1/2 cup unsalted butter, melted
1 cup mini marshmallows

Directions

1. Preheat the oven to 350°F and lightly grease a medium oven-safe glass casserole dish.

2. Spread the cubed watermelon evenly in the bottom of the prepared casserole dish.

3. Sprinkle the dry strawberry cake mix powder evenly over the watermelon, covering the fruit as much as possible.

4. Drizzle the melted butter all over the cake mix, then scatter the mini marshmallows across the top.

5. Bake for 40 to 45 minutes, or until the top looks lightly golden in spots and the watermelon is bubbling around the edges.

6. Let the dessert rest for 10 minutes before scooping and serving warm.

Variations & Tips

Add berries: Mix in 1 cup of sliced strawberries or raspberries with the watermelon for an even fruitier flavor and a prettier red filling.

Use less sweetness: If you want to tone down the sweetness a bit, reduce the marshmallows to 1/2 cup and serve with unsweetened whipped cream or plain Greek yogurt.

Chill the watermelon first: Very cold watermelon cubes hold their shape a little better while you assemble the dessert, which is helpful if you are prepping this quickly after work.

Watch for extra juice: Watermelon naturally releases a lot of liquid as it bakes, so this dessert is meant to be soft and spoonable, almost like a cobbler. Letting it rest before serving helps the syrup settle.

Try a crunchier top: For a slightly crisper finish, make sure the butter is drizzled as evenly as possible over the dry cake mix so fewer dry patches remain on top after baking.