In a large bowl add strawberries, rhubarb, cornstarch, and granulated sugar and gently mix together. Place in a 9x13 baking dish.
In a medium bowl mix together flour, oats, brown sugar, salt, and cinnamon. Add in melted butter, using a fork mix the butter in until it becomes a wet crumble mixture. Spread crumble over strawberries and gently pat.
Bake uncovered for 35-40 minutes or until the top is crisp and lightly browned and the fruit is bubbling.
Allow to cool 10-15 minutes then serve with ice cream or whipped cream.
Video
Notes
Make sure to cut your strawberries into chunks, not slices, if cut too thin/small they will turn to mush while baking.You can adjust the sugar based on the sweetness of the strawberries.Store leftovers in an airtight container in the refrigerator for 3-4 days.Frozen strawberries: Although fresh holds up much better after baking. If you need to use frozen strawberries I recommend letting them thaw in a large bowl overnight and not adding any extra juice that comes out into the bowl.No Rhubarb? Just add 2 addition cups of strawberries.