Preheat oven to 375 degrees. In a large bowl, cream butter and sugar until light and fluffy. Add eggs, one at a time, beating well after each addition.

Beat in buttermilk, lemon juice, vanilla and zest.

Combine flour, baking powder and salt in a medium bowl. Stir into creamed mixture just until moistened. Fold in blueberries.

Fill paper-lined muffin cups three-fourths full of batter. Bake for 25-30 minutes or until a toothpick inserted in muffin comes out clean. Cool 5 minutes before removing to a wire rack to cool completely.

In a small bowl, combine confectioners' sugar, lemon juice, almond extract; drizzle over cooled muffins.