Ingredients  
1   cup (2 sticks) unsalted butter, softened, plus more for pan    
3   cups all-purpose flour (spooned and leveled), plus more for pan   
3/4   cup low-fat buttermilk    
  finely grated zest of 2 lemons    
1/3   cup fresh lemon juice (about 2 lemons)    
1 1/2   teaspoons salt    
1/2   teaspoon baking powder    
1/2   teaspoon baking soda    
2   cups sugar    
5  large eggs 
Lemon Glaze (see below)

Directions
1.   Preheat oven to 350*F, with rack in lowest position. Butter and flour two 4 1/2-by-8-inch (6-cup) loaf pans.
 
2.   In a small bowl (or liquid measuring cup), combine buttermilk with lemon zest and juice. In a medium bowl, whisk together flour, salt, baking powder, and baking soda. 

3.   With an electric mixer, cream butter and sugar until light and fluffy. Add eggs, one at a time, beating until incorporated after each. 

4.   With mixer on low, add flour mixture in three parts alternately with the buttermilk mixture in two, beginning and ending with flour; beat just until smooth (do not overmix). 

5.   Divide batter evenly between pans; smooth tops. Bake until a toothpick inserted in centers comes out clean, 50 to 60 minutes (tent with foil if browning too quickly). Cool 15 minutes in pan. Turn out cakes onto a rack; cool completely before glazing. 

6.   Set rack with cakes over a baking sheet lined with waxed paper. Pour glaze over cakes, letting it run down the sides; let dry, about 30 minutes.  Makes 2 loaves.

Note: Two cakes, or one: The batter can also be baked in a 12-cup buttered and floured nonstick Bundt pan; the cooking and cooling times are the same.

Lemon Glaze  
2   cups confectioners’ sugar    
3 to 4   tablespoons fresh lemon juice
 
1.   Place confectioners’ sugar in a medium bowl or liquid measuring cup; stir in lemon juice (glaze should be thick, yet pourable). Add more sugar or lemon juice, as necessary, to achieve desired consistency.    

Source:  www.marthastewart.com