In a large bowl, gently toss together blueberries and white sugar; set aside.
In a separate large bowl, combine flour, oats and brown sugar. Cut in butter until crumbly. Press half of mixture in bottom of 8x8 baking dish. Cover with berries. Sprinkle remaining crumble mixture over berries.
Bake in the preheated oven for 30 to 40 minutes, or until berries are bubbly and topping is golden brown.