Made from super simple ingredients, and not too many of them at that, this rhubarb crisp is the perfect essence of spring! Cinnamon and orange combine with the tartness of rhubarb and oats to make a delicious treat!
Preheat oven to 350°F. Grease a 9x9 baking dish and set it aside.
In a large bowl, combine the rhubarb, white granulated sugar, instant tapioca, and orange juice. Stir to combine and pour into the prepared baking dish.
In the same large bowl, combine the oats, flour, brown sugar, and cinnamon. Stir to combine and add the butter. Using hands or a pastry cutter, rub the butter pieces into the mixture until it resembles coarse cornmeal with pieces of butter the size of a pea or smaller.
Pour the streusel mixture over the rhubarb and spread it to an even layer. Bake in the preheated oven until bubbling throughout, 40-55 minutes. Remove from oven and cool 10-15 minutes before serving.