1 quart fresh blueberries (about 4 cups you can use more blueberries if desired I most always do!)
3/4 cup sugar (or to taste)
2 tablespoons cornstarch
1 cup water
2 -3 tablespoons lemon juice
1/2 teaspoon vanilla
1 cup all-purpose flour
3/4 cup regular oats
1 cup brown sugar
1 1/2 teaspoons cinnamon
1/2 cup butter, melted (no substitutes)
Set oven to 350 degrees F.
Prepare an 11 x 7-inch baking dish (can use a 13 x 9-inch but it will not be as high).
Spread the blueberries in the bottom of the prepared baking pan.
In a small saucepan over medium heat combine the sugar, cornstarch, water and 2-3 Tbsp lemon juice; cook and stir until thick and clear, then add in the vanilla.Pour over, then gently stir in the cooked mixture with the blueberries.
In a bowl combine the flour with oats, brown sugar and cinnamon.
Add in the melted butter; mix until crumbly (I start mixing with a spoon then finish mixing with my hands).
Sprinkle over the top of blueberries (there will be a couple of empty spots that is okay, there may seem like a lot of crumble but it will settle when baking).
Bake for 30-35 minutes, or until blueberry mixture bubbles and the topping is brown.
Serve with ice cream-- enjoy!