1. Preheat oven to 350F. Butter and flour one 12-cup bundt pan or two 4 ½ x 8-inch loaf pans; set aside.
2. In a large bowl, whisk together flour, salt, baking powder, and baking soda; set aside. In a small bowl or liquid measuring cup, stir together buttermilk and lemon juice; set aside.
3. In the bowl of an electric mixer, cream butter, sugar, and lemon zest until light and fluffy, about 3 minutes. Add eggs, one at a time, beating until incorporated, scraping down the sides of the bowl after each addition. Add lemon extract and stir to combine.
4. Add flour mixture in three parts, alternating with buttermilk mixture, beginning and ending with flour mixture. Beat until just combined.
5. Pour batter into prepared pan and smooth top. Bake until a cake tester inserted in the center of the cake comes out clean, about 50 to 60 minutes. (Cover top with foil if the top is browning too quickly.) Cool 15 minutes in the pan. Turn out onto a wire rack and cool completely before glazing.
6. Make glaze- In the bowl of an electric mixer, cream together cream cheese and butter until smooth. Add zest and lemon extract and beat until combined. Add in confectioners’ sugar, beating until smooth. Add heavy cream, a tablespoon at a time, until the glaze reaches the desired consistency. Spread on cooled cake