Preheat the oven to 350 degrees F and spray a 9x5 loaf pan with non-stick spray.
In a large bowl, beat eggs on low with an electric mixer.
Add sugar, and butter and beat until smooth.
Pour in milk and vanilla extract and mix just until combined.
In a medium bowl toss blueberries with cornstarch. They should all be covered well, and set aside.
In a separate mixing bowl combine flour, baking powder, baking soda, and kosher salt.
Slowly incorporate the flour mixture into the egg-sugar mixture with the mixer on low just until combined.
Gently fold in blueberries and lemon zest.
Pour the batter into the prepared pan. The batter will be sticky!
Make a small cut lengthwise about 1/2 inch deep in the center of the bread.
Bake for 1 hour and 15 minutes (it may take you slightly more, depending on the oven) or until the toothpick inserted into the center comes out clean or with a few breadcrumbs.
Let the bread cool in the tin for 10 minutes, and transfer to a wire rack to cool completely.
Drizzle the cooled bread with glaze.
Cut into 10-12 thick pieces and enjoy.