For the Cake

Nonstick cooking spray
1 cup (2 sticks) unsalted butter, room temperature
2 cups granulated sugar
4 large eggs, room temperature
2 1/2 tablespoons freshly grated lemon zest (from 4 large lemons)
2 1/2 tablespoons freshly squeezed lemon juice (from 2 lemons)
3 cups plus 1 tablespoon all-purpose flour
1/2 teaspoon baking soda
1/2 teaspoon coarse salt
1 cup buttermilk
1 1/2 cups fresh blueberries (9 ounces)

For the Glaze

1/2 cup confectioners' sugar
1/2 cup freshly squeezed lemon juice (from 4 lemons)
2 teaspoons freshly grated lemon zest (from 1 lemon)