Preheat your oven to 350℉ (or 180℃) and lightly spray/grease an 8x11 (or 2 to 3 quart) baking dish.
In a large bowl toss together the rhubarb, brown sugar, cornstarch, lemon zest, lemon juice and vanilla extract. Toss we'll to combine and set off to the side.
MAKE THE CRUMB TOPPING:
In a mixing bowl, measure and add flour, oats, sugar, cardamom, nutmeg, ginger and salt.
Add the butter and using a pastry cutter, blend the butter into the dry ingredients until it small crumbs are formed.
Transfer the rhubarb to the prepared pan and spread evenly.
Sprinkle the crumble over top of the rhubarb and bake for 30 to 40 minutes or until the crumb is golden brown and the rhubarb is tender and bubbly.
Allow the crumble to cool 20 to 30 minutes before serving. We like it slightly warm with a scoop of vanilla ice cream.
Notes
Nutrition Disclaimer:All information presented on this site is intended for informational purposes only. I am not a certified nutritionist and any nutritional information shared on SimplyScratch.com should only be used as a general guideline.The nutritional information is for the crumble only and does not include and additional toppings (I.e. ice cream).