Preheat oven to 350°.
Place 12 decorative paper muffin cup liners into muffin cups.
To prepare cupcakes, lightly spoon 1 1/2 cups flour into dry measuring cups; level with a knife. Measure 1 tablespoon flour; level with a knife. Sift together 1 1/2 cups flour plus 1 tablespoon flour, granulated sugar, baking powder, 1/4 teaspoon salt, and baking soda in a large bowl. Combine melted butter and egg in another large bowl; stir with a whisk. Add buttermilk, milk, and 1 teaspoon rind to butter mixture; stir with a whisk. Add buttermilk mixture to flour mixture, stirring just until moist. Toss blueberries with remaining 1 tablespoon flour. Fold blueberries into batter. Spoon batter into prepared muffin cups. Bake at 350° for 25 minutes or until a wooden pick inserted in center comes out clean. Cool in pan 5 minutes on a wire rack; remove from pan. Cool completely on wire rack.
To prepare frosting, place cream cheese, 2 tablespoons butter, 1 teaspoon rind, vanilla, and 1/8 teaspoon salt in a bowl; beat with a mixer at medium speed just until blended. Gradually add powdered sugar (do not overbeat). Stir in juice. Spread frosting evenly over cupcakes; garnish with blueberries, if desired. Store, covered, in refrigerator.