Preheat the oven to 350 degrees F and take out an 8x8 dish. Cut the rhubarb into roughly 1 inch chunks using a large sharp knife and cutting board and place them in the 8x8 dish.
Cut the strawberries in half and place them in the dish with the rhubarb.
Measure out the remaining filling ingredients with measuring spoons and cups and put them in the bowl with the fruit. Mix everything together with a large spoon and pour into an 8x8 baking dish, spreading the fruit out evenly.
Cover the dish with foil and place it in the oven to cook for 15 minutes.
While the strawberries and rhubarb are cooking, measure out then add in the topping ingredients to a large bowl. Mix everything together with a spoon and set aside.
When the fruit has cooked for 15 minutes, take the dish out of the oven, remove the foil (you can toss it) and mix the fruit up with a spoon.
Spoon the topping over the strawberries and rhubarb, covering them as best you can but not pressing the topping down. Return the dish to the oven, uncovered, and cook for 40 minutes, turning the dish around 180 degrees after 20 minutes to prevent uneven browning.
Remove the dish and let cool for 5-10 minutes, then serve!