Pre-heat your oven to 350 degrees F.
Combine the filling ingredients into a large sauce pan and place on medium heat. Heat the mixture, stirring often, until it thickens, then cook another 5 minutes. Pour the mixture into a well-greased deep dish 9x9 pan. (Tip: If you're in a rush or want to save yourself some work, try using 9 cups of Riverbend Plantation's Saskatoon Berry Pie Filling instead of making your own filling!)
Combine the flour, sugar and oats together; cut in the butter until crumbly. Sprinkle of top of the filling.
Bake the crisp in oven for 20-25 minutes, until the topping browns and crisps up. Remove from the oven, cool slight and serve warm.
Serve warm or cold, with our without vanilla ice cream!