Recipe Card

Preheat the oven to 375°F and prepare the baking dish with melted butter.
Mix sugar and cornstarch in a bowl, then add rhubarb and lemon juice, and transfer to the baking dish.
Combine oats, flour, brown sugar, salt, and cinnamon in a bowl, then add melted butter and mix. Scatter on the rhubarb.
Bake for 35-45 minutes, allow to cool, and serve with ice cream or whipped cream.