In a saucepan, combine blueberries, sugar and orange juice. Bring to a boil, reduce heat and simmer until tender, about 10 minutes. Dissolve cornstarch in 2 tablespoons water and then whisk into blueberries, stirring until thickened, about 1 minute. Set aside to cool for at least 1 hour.
In a large bowl, whisk together the oats, flour, sugar, orange rind and salt; with a pastry blender or a fork, cut in butter until coarse crumbs. Press half (about 2 ½ cups) into an 8-inch square parchment paper-lined metal cake pan. Spread blueberry filling and then sprinkle the remaining oat mixture, pressing lightly.
Bake in the center of 350°F oven until light golden, about 45 minutes. Let cool before cutting into squares.
Enjoy!
Notes
Recipe source: Canadian Living
Recipe by Salu Salo Recipes at https://salu-salo.com/blueberry-oatmeal-squares/