Weigh or lightly spoon flour into dry measuring cups, and level with a knife. Combine flour, baking powder, baking soda, and 1/2 teaspoon salt in a bowl, stirring well with a whisk.
Place granulated sugar and 12 tablespoons butter in a large bowl; beat with a mixer at medium speed until well blended. Add eggs, 1 at a time, beating well after each addition. Beat in vanilla and rind. Add flour mixture and buttermilk alternately to butter mixture, beginning and ending with flour mixture.
Spoon batter evenly into prepared pans. Bake at 350° for 18 minutes or until a wooden pick inserted in centers comes out with moist crumbs clinging. Cool 5 minutes in pans on a wire rack; remove from pans.
Dust tops of cakes with powdered sugar.
VARIATION 1: Cranberry-Orange Bundt Cakes
Prepare Buttermilk Bundt Cakes batter, reducing vanilla to 1 teaspoon, omitting lemon rind, and decreasing buttermilk to 3/4 cup. Combine 1 cup sweetened, dried cranberries and 1/2 cup fresh orange juice in a microwave-safe dish. Microwave at HIGH for 1 minute; let stand 10 minutes. Fold cranberry mixture into batter. Omit 1/3 cup powdered sugar. Combine 2 cups powdered sugar, 1/4 cup fresh orange juice, 1 tablespoon melted butter, and 2 teaspoons grated orange rind, stirring until smooth. Dip tops of cooled cakes in glaze; let stand until set. CALORIES 331; FAT 4g (sat 6g); SODIUM 262mg
Dip & Swirl: For a glaze that completely covers the cakes, dip the tops into glaze and swirl them around a bit to make sure the glaze coats and sticks.
VARIATION 2: Hummingbird Bundt Cakes with Bourbon Glaze
Prepare Buttermilk Bundt Cakes, adding 1 1/2 teaspoons ground cinnamon to flour mixture. Decrease vanilla to 1 teaspoon, and omit lemon rind. Fold 1 cup chopped ripe banana, 1/2 cup chopped toasted pecans, and 1 (8-ounce) can crushed pineapple into batter. Combine 1/2 cup powdered sugar, 1 tablespoon bourbon, 1 tablespoon melted butter, and 1/4 teaspoon vanilla; stir until smooth. Drizzle over cakes. CALORIES 291; FAT 9g (sat 4g); SODIUM 269mg
Doubling Up: You'll only need a touch of the bourbon glaze, but for sugar hounds, you can double the glaze and garnish with more.