Preheat the oven to 375 degrees. In a medium bowl, combine the first 4 ingredients; spoon into a 11 x 7-inch baking dish.
Combine your flour, brown sugar, oats and cinnamon and cut in the butter with a pastry knife until the mixture reveals coarse meal. Sprinkle over blueberry mixture and bake at 375 degrees for 30 minutes or until bubbly.