Preheat the oven to 350°F. Grease and flour a 10-inch (10-cup) bundt cake pan.
In the bowl of a stand mixer fitted with the paddle attachment, beat together the butter, cream cheese and sugar until smooth. Add the eggs and egg white, one at a time, beating well between each addition.
Add the lemon zest and vanilla extract and beat until combined.
Remove 2 tablespoons of flour from the 3 cups and add it to a small bowl along with the blueberries. Toss them together until the blueberries are well-coated in the flour then set them aside.
Sift together the remaining flour, baking powder, baking soda and salt. Alternately add the dry ingredients and the sour cream to the batter, beating between each addition. Using a spatula, fold in the blueberries then transfer the batter to the prepared cake pan. Bake the cake for 50 minutes or until a toothpick inserted comes out clean. Allow the cake to cool for 10 minutes in the pan before inverting it onto a baking rack to cool completely. While the cake cools, prepare the glaze.