First melt the butter. Add the sugar and whip it together with a whisk. Then add the eggs. Mix well. Add the sour cream. Mix well. Never beat. Add the vanilla, lemon zest & lemon juice & mix. Combine dry ingredients in separate bowl: baking powder, salt and flour. Add dry ingredients to wet & mix again. Remember – never beat this one.
Spray the heck out of the inside of the bundt pan with some non-stick spray. Then flour the entire inside. Shake out excess flour. Once your bundt pan is sufficiently greased, floured and nothing will stick inside it, it is time to fill it.
Pour the batter in the pan, top with blueberries. Gently “push” the berries into the cake (just under the surface).
Bake it 340 degrees for 1 hour, or until a toothpick comes out clean.
Let cool 10-15 minutes & then turn out of bundt pan.
To make the Glaze:
First melt the butter. Mix in vanilla, salt, lemon juice & milk. Add powdered sugar. This should not be “spread-able.” This is a runny-ish icing. You want it to be fluid so it will run down the sides of the coffee-cake and fill the grooves and look pretty. Spoon on top of cool bundt cake and let it run down the sides.