Ingredients for filling:
2 1/2 cups fresh or frozen blueberries
1/2 tsp vanilla extract
1/2 Tbsp lemon juice
1 1/2 Tbsp white whole wheat flour
Pinch of sea salt

Ingredients for Topping:
1/2 cup rolled oats
2 Tbsp white whole wheat flour
3 Tbsp cup light brown sugar
Pinch of sea salt
3 Tbsp softened butter, unsalted

Preheat oven to 375ºF and spray a small 6 x 8 inch casserole dish with nonstick cooking spray.
Combine all of the ingredients for the filling in a large bowl – transfer to the baking dish and set aside.
In a separate bowl, prepare the crumble topping. Combine all ingredients to create an even crumble topping.
Evenly spread crumble topping over the berries.
Place in the oven and bake at 375ºF for 30 minutes.