For the cake:

• Preheat oven to 350°F/180°C with the rack in the center of the oven.
• Coat a 9-inch/23 cm/12 cup bundt pan lightly with flavorless oil.
• To a bowl, mix the flour, baking powder, baking soda and salt.
• To a separate bowl or stand mixer, beat butter and sugar on medium speed until very light in color and fluffy, about 5 minutes. Continue beating the butter while adding eggs, one at a time.
• Add ⅓ of the flour and mix on low. Add ½ of the sour cream and beat. Repeat these steps, ending with flour. Add the limoncello and lemon zest. Mix until smooth, don't over beat.
• Pour batter into prepared bundt cake pan and smooth the top. Bake for 27 minutes, rotate the cake and reduce the oven temperature to 325°F/165°C. Continue to bake for more 27 more minutes or until a long skewer when inserted into the center comes out clean. If you're using a dark grey bundt pan, cooking time may be shorter. Also, baking times will depend on your oven.
• Remove from the oven and cool in the bundt pan (do not turn over yet) on a wire rack for 20 minutes. After 15 minutes, place a wire rack on top and turn the cake out and remove the pan. Cool on the wire rack completely.
• Make the glaze while the cake cools: Add the powdered sugar and limoncello to a bowl and mix until smooth.Drizzle over the cooled cake.