These wholesome bars are just like Starbucks blueberry squares (if not better!) My favorite thing about this recipe is the oatmeal base/crumble topping. It is so versatile and makes enough for a generous amount on the top and bottom because c'mon... isn't that everyone's favorite part?! I use this same oatmeal crust recipe with a multitude of different fillings, including swapping strawberries for the blueberries.
- Filling: In saucepan, bring blueberries, sugar and orange juice to boil; reduce heat and simmer until tender, about 10 minutes. Whisk in cornstarch and boil, stirring, until thickened, about 1 minute. Place plastic wrap directly on surface; refrigerate until cooled, about 1 hour or up to 1 day before using.
- Base/Topping: In a large bowl, stir together the oats, flour, brown sugar, salt and baking soda. Cut in the butter to form a crumbly mixture. Reserve 1 1/2 cups of the crumbs, and pat the rest evenly into the bottom of a greased 9 x 13 inch pan.
- Spread the blueberry mixture over the base. Crumble the reserved amount of the base/topping over the blueberry mixture.
- Bake at 350 degrees F until light golden, about 40-45 minutes. Let cool completely on rack as these cut better when they are fully set. (Make-ahead: Cover and refrigerate for up to 2 days or overwrap with heavy-duty foil and freeze for up to 2 weeks.).