Lemon Buttermilk Cake

1. Preheat the oven to 350°F. Generously grease and flour a (9-inch) Bundt pan or line 36 muffin tins with paper liners.
2. In a stand mixer fitted with the paddle attachment, combine the butter and sugar and beat on medium speed until the mixture is smooth and light in texture, about 5 minutes. While the butter is beating, sift together the flour, baking soda, and salt, and set aside. In a small bowl, combine the buttermilk, lemon zest, and 4 tablespoons of the lemon juice and set aside.
3. Add the eggs to the butter-sugar mixture, one at a time, beating well and scraping down the bowl after each addition. In 3 additions, alternate adding the sifted dry ingredients and the wet ingredients to the butter-sugar mixture, stirring on low until just incorporated.
4. Pour the batter into the prepared Bundt pan or fill each muffin cup two-thirds full with batter. Bake until the center of cake springs back when touched and a skewer inserted near the center comes out clean, 1 hour to 1 hour and 15 minutes. Bake cupcakes until they rise in a dome shape and spring back when lightly pressed with a fingertip, 16 to 20 minutes.
5. Remove the cake from the oven and let cool completely in the pan on a wire rack. Release the sides and bottom of the cake from the pan with a narrow metal spatula or knife. Invert the pan and turn out the cake. Place a wire rack in a baking pan and set the cake, right side up, on the rack.
6. In a small bowl, combine the confectioner's sugar, the remaining 1 tablespoon lemon juice, and 1 tablespoon cold water and stir until very smooth. Add a little more confectioners' sugar or water as necessary to achieve a glaze consistency (similar to that of honey). Spoon the glaze evenly over the cake. When the glaze has firmed, transfer the cake to a plate. Slice and serve at room temperature.