¾ cup (75g) old-fashioned oats (gluten-free if necessary and measured like this)
¼ cup (30g) whole wheat flour or millet* flour (measured like this)
1 tsp. ground cinnamon
2 tbsp. (30mL) pure maple syrup, room temperature
1 ½ tbsp. (21g) unsalted butter, melted
6 cups (840g) blueberries
3 tbsp (24g) cornstarch
Preheat the oven to 350°F, and coat an 8”-square pan with nonstick cooking spray.
To prepare the topping, whisk together the oats, flour, and cinnamon in a small bowl. Make a well in the center. Pour in the maple syrup and melted butter. Stir until fully incorporated.
To prepare the filling, toss the blueberries with the cornstarch in a large bowl until completely coated.
Transfer the filling to the prepared pan, and sprinkle evenly with the topping. (The topping tends to clump, so try to break it up into fairly small pieces.) Bake at 350°F for 45-55 minutes or until the juice is bubbling at the sides of the pan. Cool completely to room temperature; then refrigerate for at least 3 hours before serving to allow the juices to fully thicken.