Step 1

Preheat oven to 350F (175C). Line an 8 inch (20 cm) square baking pan with parchment paper and spray with nonstick cooking spray. Set aside.

Step 2

Oat layers: In a food processor, process 1 and 1/2 cups (135 g) of the oats into a fine flour. In a large bowl, combine (use a fork) the oat flour, remaining 1 cup (90 g) oats, banana, flaxseed meal, water and salt until combined and crumbly.

Step 3

Filling: In a large bowl, coarsely crush the blueberries with a fork. Sprinkle the arrowroot over berries and stir to combine. If desired, add a pinch of salt.

Step 4

Assembly: Firmly press half of the oat mixture into the prepared pan, evenly tamping down. Evenly spread with the blueberry filling. Coarsely crumble remaining oat mixture over filling.

Step 5

Bake in the preheated oven for 25 to 30 minutes or until filling is bubbly and topping is golden. Cool completely, in the pan, on a wire rack. Refrigerate until cold.

Step 6

Remove from pan and cut into 16 bars.