Preheat the oven to 350°F.
Line an 8x8 baking dish with parchment paper, then coat it with nonstick cooking spray.
To make the crust, add pulverized graham cracker, oil, lemon zest, and salt to the bowl of a food processor; pulse to combine. Press mixture into the bottom of the prepared pan. Bake for 10 to 15 minutes, or until crust is golden brown. Then remove pan from the oven and set aside to cool.
To make the filling, process the egg, egg whites, yogurt, maple syrup, lemon juice in a blender until smooth. Stir in the fresh blueberries. Pour the filling onto the prebaked crust.
Transfer pan to the oven and bake for 25 to 30 minutes, or until the center is set. Remove pan from the oven and place on a wire rack to cool completely. Cut into 16 equal-sized squares and serve chilled or at room temperature.