Rhubarb Crisp with cake mix

https://www.food.com/recipe/rhubarb-crisp-easy-30381

INGREDIENTS

2 cups sugar
1⁄4 cup flour
5 -6 cups chopped rhubarb
1 package yellow cake mix
3⁄4 cup butter, melted
chopped nuts, if desired

• Mix flour and sugar together, add rhubarb, tossing well.
• Place in a 9″ x 13″ baking dish.
• Sprinkle dry cake mix and chopped nuts, if using, over rhubarb mixture.
• Drizzle melted butter over all.
• Bake at 350 degrees F for 50- 60 minutes.
• Serve warm topped with vanilla ice cream, if desired.