While rhubarb is not a traditional ingredient for many, this rhubarb and berry crisp is a perfect springtime treat! Since rhubarb is tart, adding it with raspberries and blueberries is a great solution. With an oat topping that adds a bit of crunch, this recipe will be a favorite in no time!
Preheat oven to 375°F. Grease a 9x9 baking dish and set aside.
Mix together the cleaned and prepared rhubarb, raspberries, and blueberries. Add the sugar, tapioca, lemon zest, lemonn juice, and vanilla. Pour into the prepared baking dish and prepare the crumble topping.
Combine the flour, oats, white sugar, brown sugar, cardamom, and salt. Mix together and add the butter. Using fingers, combine the butter and dry ingredients until completely combined. Evenly sprinkle the crumble over the fruit.
Place the baking dish on a parchment-lined baking sheet and bake in the preheated oven until bubbling throughout and browned on top, 45-60 minutes. If the top gets too brown, cover with foil.