Step 1

Grease and flour a bundt or tube pan; Set aside. Preheat the oven to 350° (177°C).

Step 2

Cream butter (3/4 cup) and sugar (1 1/2 cups) together in a large bowl until light and fluffy. Add in the eggs (one at a time, mixing until yellow disappears, then the vanilla (1 teaspoon).

Step 3

In a separate bowl, whisk together flour (3 cups), baking powder (1 1/2 teaspoons), baking soda (3/4 teaspoon), and salt (1/4 teaspoon).

Step 4

To the creamed butter and sugar mixture add, alternately, flour mixture and sour cream (1 cup), beginning and ending with flour mixture, beating well after each addition.

Step 5

In a small bowl combine brown sugar (1/4 cup), flour (1 tablespoon), and cinnamon (1/2 teaspoon); Set aside.

Step 6

Pour a third of the batter into a prepared baking pan, spreading evenly. Sprinkle half of the brown sugar mixture over the batter in the pan, then place half of the blueberries on top. Repeat layers then top with the remaining batter.

Step 7

Bake until the cake tester inserted in the center comes out clean, about 55-65 minutes or until. Allow cake to cool in the pan, set on a wire baking rack, for 10 minutes. Remove from pan and let cool completely on the wire baking rack.

Step 8

Meanwhile, prepare the glaze. In a medium mixing bowl, whisk the powdered sugar (1 cup) and 2 tablespoons of milk together until smooth. Add more milk as necessary to obtain a pouring consistency. Drizzle glaze over the cooled coffee cake. Garnish with fresh blueberries (1/2 cup).