These wholesome, energy-boosting bars are great for a midday snack, workout, or breakfast on-the-go. They're made with wholegrain oats, fresh blueberries, ground almonds, bananas, and flavorings of your choice.
Preheat the oven to 350F. Line an 8-inch square baking tray with parchment paper and spray lightly with non-stick cooking spray.
For the oat layers: In a food processor, blitz 1.5 cups of oats into a fine flour. Then in a large bowl, using a fork combine the oat flour, remaining 1 cup of rolled oats, mashed banana, ground nuts, melted butter, water, salt, and flavoring of your choice until combined and crumbly.
For the blueberry filling: In a large bowl, using a fork, coarsely crush the blueberries. Sprinkle them with the cornstarch and optional flavoring, if using. Mix well.
Firmly press half of the oat mixture into the prepared pan, patting down to form a crust. Evenly spread over the blueberry filling, and finish by coarsely crumbling the remaining oat mixture over the top.
Bake in the pre-heated oven for 25-30 minutes, until the filling is bubbling and the topping is golden.
Cool completely in the pan on a wire rack. Once cool, cut into 10 bars.