• Preheat oven to 350°F/175°C. Spray the bottom and sides of a 9x13 cake pan with baking spray (flour combined with baking spray).

For the Lemon Blueberry Cake:

• In a bowl whisk together the flour, sugar, cornstarch, baking powder, baking soda, and salt. Set aside.
  
• Zest two fresh lemons to create 2 tablespoons of lemon zest.
• In a separate bowl combine vegetable oil, water, lemon zest, and vinegar. Stir to combine. Add lemon juice mixture to the flour mikxture and stir to combine.
  
• Keep the frozen blueberries frozen to the very end. Add a tablespoon or two of the flour mixture and toss until distributed. If using fresh blueberries, no other work needs to be done.
• Spread 1/4 of the plain batter into the prepared pan. Use a spatula to spread it across the pan evenly. Sprinkle a few blueberries over the batter.
• Pour and spread the batter over the top of the blueberries.
  
• Place in the oven on the middle rack and bake for 50 minutes.

For the Lemon Glaze:

• While the cake is baking prepare the Lemon Glaze by combining powdered sugar with the lemon zest and lemon juice. Stir to combine. Or you can use vegan lemon frosting.
• When the cake is done, remove it from the oven. Drizzle the glaze over the cake. Allow it to cool for 10 minutes or so.
• Store the cake in the fridge for up to 5 to 7 days. It can be frozen for up to 2 months.