• Preheat the oven to 350°F. Using non-stick cooking spray, lightly grease an 8x8-inch baking pan. Line the pan with parchment paper so that the paper hangs out over the edges of the pan. (This will help with removing the bars for serving.) Lightly spray the parchment paper.
• In a small bowl , stir together the water and flaxseed. Set aside.

For the crust:

• Into the bowl of a food processor, add the flour, sugar, butter, cinnamon, and salt. Process for 1 minute, or until the mixture is crumbly.
• Remove 1/4 of the crust mixture and set aside. Press the remaining crust mixture evenly into the prepared pan.

For the filling:

• In a medium-size mixing bowl, whisk together the flaxseed mixture, sour cream, sugar, lemon juice, cornstarch, flour, vanilla extract, and cinnamon. Stir in 1 cup of the blueberries.
• Pour the filling mixture over the crust then sprinkle with the remaining 1 cup blueberries.
• Crumble the reserved crust mixture in an even layer over the top of the filling.
• Bake for 1 hour.
• Allow to completely then refrigerate for 1 hour to set. Cut into bars and serve.