Preheat oven to 350°. In a large bowl, cream butter and sugar until light and fluffy, 5-7 minutes. Beat in eggs and vanilla.
In another bowl, combine flour, baking powder and salt; add to creamed mixture alternately with milk, beating well after each addition. Fold in blueberries.
Scoop into 12 greased 4-in. fluted tube pans. Place pans on a large baking sheet. Bake until a toothpick inserted in center comes out clean, 30-35 minutes. Cool for 10 minutes before removing from tube pans to wire racks to cool completely.
For icing, in a small bowl, combine confectioners' sugar, milk and lemon juice; drizzle over cakes. If desired, garnish with additional blueberries.
