Preheat the oven to 350 F, or 175 C, and place the baking paper on a baking tray. I used a 8 × 8 container, but any container will be OK only there will be a difference in the size and thickness of the bars.In a large, deep bowl, add the oatmeal, cinnamon, baking powder and salt. Stir and add the maple syrup. Stir well again until the maple syrup is mixed with the other ingredients.In a separate bowl, add all the other ingredients (except the blueberries) and stir until a smooth, liquid mixture is obtained.Add this mixture to the oatmeal mixture and stir until it is completely combined. Add the blueberries and gently stir in the mixture (leave a few to finally add to the surface of the mixture)Add the mixture to the prepared baking pan and add the preserved blueberries to the surface.Bake for 35 minutes, or until the surface of the cake gets a golden color.Allow to cool before cutting into bars. Do not worry if the cake breaks or you do not get perfect bars. Serve with Greek yogurt and extra fresh fruit or just as it is.