For the pound cakes:
Preheat the oven to 325-degrees. Spray 3 small loaf pans, 8-½” x 4-½”, with a cooking spray and line with a sheet of parchment paper, pressing into the bottom and edges of the pans.
Using a large stand mixer, beat the butter on low speed until it becomes creamy. Raise the speed to medium and continue beating until it is very light and fluffy, looking much like whipped cream, about 4 to 5 minutes. Scrape down the sides and bottom of the mixing bowl to make certain all the butter is whipped thoroughly.
On medium speed, add the sugar, about ¼ cup at a time allowing the sugar to blend into the butter before adding more. Once all the sugar has been combined with the butter add the eggs one at a time.
Pour in the buttermilk, blending in using medium-low speed.
Using separate bowls, sift together the flour, baking soda, and kosher salt three times. Don’t’ skip this step; it makes a difference in the light texture of your cake.
On low speed, add the dry ingredients to the batter, blending in about ¾ cup at a time, beating just until the flour disappears.
Stir the lemon zest into the lemon juice and add to the batter along with the vanilla extract and lemon extract, blending into the batter on low speed.
Divide the batter evenly between the 3 prepared loaf pans.
Bake the pound cakes on the center rack of your oven at 325-degrees for about 50 minutes or until the cakes are golden and a toothpick inserted in the center comes out clean.
Allow the cakes to cool in the pans for about 10 minutes, then transfer to a wire rack. Glaze while the cakes are still warm.
For the glaze:
Whisk the powdered sugar together with the lemon zest, lemon juice, vanilla extract, and lemon extract until very smooth.
Using a toothpick, poke holes across the tops of the cakes. Spread the glaze over the tops of each cake.