6 cups / 650gchopped rhubarb(see notes on how to prepare)
¾ cup / 150ggranulated sugar
¼ cup / 30gcornstarch
1 tablespoon / 15glemon juice
½ cup / 113gdairy-free butter
½ cup / 70ggluten-free all-purpose flour
¾ cup / 67.5ggluten-free rolled oats
¼ cup / 50ggranulated sugar
¼ cup / 50gbrown sugar
¼teaspoonfine sea salt
Preheat the oven to 375°F/190°C. Put a 2qt baking dish (or an 8x8 inch square pan) on a baking sheet, and set aside.
In a large bowl, combine the sugar, cornstarch, cinnamon, and lemon zest. Add the chopped rhubarb and toss until evenly coated. Add the lemon juice and toss it again. Pour it into the baking dish and set it aside.
In a separate bowl, combine the gluten free flour, oats, granulated sugar, brown sugar, salt, and cinnamon. Add the butter and use your hands to pinch the butter and incorporate it into the flour mixture until it resembles course crumbs.
Evenly sprinkle it over the rhubarb mixture and bake it for 45 minutes. Let it cool for at least 15 minutes before serving.
How to prepare the rhubarb: Cut the tops and bottoms off the rhubarb stalks. Make sure to cut off the leaves as they're poisonous. Chop the rhubarb into 1 inch pieces.