Preheat the oven to 350°
Layer the rhubarb in the bottom of a 9x13 pan, if it's frozen do not thaw it, just let it thaw enough to break apart
Sprinkle the Jello over the top
Sprinkle the dry cake mix over the Jello
Pour the melted butter on top of the cake mix
And drizzle the water over the top of everything
Bake in the preheated oven 55-60 minutes or until the top is set in places and the fruit is bubbling hot
Cool a little before serving, this doesn't cut like a cake so be ready to scoop it up!
