
Preheat the oven to 350℉. Lightly grease and flour a 9-10" bundt pan. Set aside.
In a small bowl, combine the flour, baking powder, and salt.
In the large bowl of a standing electric mixer, cream together the sugar and butter until smooth. Then slowly beat in the eggs, sour cream, and vanilla extract. Then slowly beat in the flour mixture. Beat just until all the ingredients are combined. Fold in the blueberries and pour the batter into the bundt pan.
Bake for 50 minutes or until a toothpick inserted into the center comes out clean. Cook on a baking rack for 15 minutes, then invert the pan and pop out the cake. Allow the cake to cool completely. Use the glaze below to ice the cake.
Whisk the butter, powdered sugar, vanilla extract, and 1 Tablespoon of milk in a small bowl. Add extra milk if you'd prefer thinner icing. Drizzle the icing on the cake once it's cooled.