01 - Preheat oven to 350°F. Lightly grease a 9×13-inch baking dish.
02 - Arrange the drained diced mangoes evenly across the bottom of the prepared baking dish.
03 - Sprinkle the dry yellow cake mix evenly over the mangoes, ensuring full coverage.
04 - Drizzle melted unsalted butter evenly across the cake mix, making sure to cover as much of the surface as possible.
05 - Bake in the preheated oven for 45 to 50 minutes, or until the top is golden brown and the mango filling is bubbling.
06 - Allow to cool slightly before serving.