As it heats, wash the blueberries and place in a large mixing bowl.
Add in the corn starch, water, vanilla extract, and granulated sugar to bueberries.
Give the blueberries a quick stir to combine the ingredients and then spread across a baking dish coated in non-stick spray.
In a small bowl, mix all the ingredients for the topping except for the butter. You might find it helpful to use a fork or potato masher to get it well combined.
After you get the dry ingredients together, pour in the melted butter and work that into the topping.
Spread the topping over the strawberries.
Place the baking dish into the oven and bake for 40 to 50 minutes or until the topping has browned and blueberries are bubbly and have burst open.
Allow to cool for a few minutes before serving with ice cream, whipped cream, or more blueberries on top.