Mix blueberries, vanilla and corn starch together in a bowl and microwave for 1 minute if you're using fresh blueberries or 1 minute and 30 seconds if using frozen.
To a separate bowl mix together oats, maple syrup, protein powder, cinnamon and salt.
Add water 1/2 tbsp at a time to the topping and mix until a crumbled texture forms.
Put all the topping on top of the halfway cooked blueberries and put back in the microwave for 1 more minute. If your crumble needs more time, microwave 10 seconds at a time.