Ingredients 1/2 cup butter, softened to room temperature 3/4 cup granulated sugar 2 cups powdered sugar 3 cups milk 3 eggs 1 teaspoon vanilla extract 1 teaspoon baking soda 2 teaspoons salt 1/4 teaspoon baking powder 2 cups all-purpose flour 1/8 teaspoon salt 1 teaspoon cinnamon 1/3 cup blueberries...