Preheat the oven to 350 degrees and spray an 8 by 8 oven safe pan with nonstick cooking spray.
Using a large spoon stir the frozen blueberries, sugar, lime juice and cornstarch together in a large bowl until mixed well. Pour into the greased pan letting the cornstarch-sugar mixture pour over the top. Set aside.
Wipe out the bowl and make the topping. Combine all the topping ingredients and cut the butter into the mixture with your hands until it resembles crumbly cookie dough. You can do it in a food processor if you prefer.
Spread the topping evenly over the blueberries and bake for 60 to 70 minutes until the top is golden brown and the blueberries are bubbly.