Preheat the oven to 350 F.
In a large mixing bowl (or bowl of an electric mixer), beat eggs on low with an electric mixer. Add sugar, butter, and beat until smooth. Stir in milk.
In a medium bowl, toss blueberries with cornstarch. They should all be covered well in it.
In a separate mixing bowl combine dry ingredients and add to wet ingredients. Mix on low until everything combines. Stir in lemon zest and blueberries.
Pour the batter into a 9 x5-inch loaf pan (greased or lined with parchment paper or foil). The batter will be sticky! Make a small cut lengthwise about ½ inch deep in the center of the bread.
Bake in the preheated oven for 1 hour and 15 minutes (or it may take you slightly more, depending on the oven!) 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, transfer to a wire rack to cool completely.
Make the glaze by combining all the ingredients. Drizzle over the cooled loaf with a spoon or a fork and let set.
Cut into 10-12 thick pieces and enjoy.