Preheat oven to 350 degrees. Prepare two 6 cup loaf pans (4 1/2-by-8 inch) by brushing with butter and then dust with flour, tapping out excess.
In a small bowl, combine buttermilk with vanilla extract and lemon extract. Add the lemon zest and juice. Set aside. Next, in a medium bowl, whisk together flour, salt, baking powder, and baking soda.
With an electric mixer on medium-high speed, cream butter and sugar until light and fluffy. Add eggs, one at a time, beating until incorporated after each and scraping down sides of bowl as needed. Reduce speed to low. Add flour mixture a little at a time, alternating with the buttermilk and beat until just smooth (do not over mix).
Divide your batter evenly between pans; shake and top on counter to smooth tops and get rid of air bubbles. Bake until a toothpick inserted in centers comes out clean, 50 to 60 minutes. Start checking them a little earlier to make sure they are not getting too brown. If they are, lay a piece of aluminum foil on top. Cool 15 minutes in pan, then turn out onto a rack to cool completely.
Stir together powdered sugar, 2 teaspoons lemon juice and enough milk for desired glazing consistency in small bowl. Drizzle over cooled cake.