If using sour milk: place 1 tablespoon of white vinegar in a measuring cup and fill with enough milk to make 1 cup. Stir few times and let sit for 2 to 3 minutes.
In a large mixing bowl, whisk together the dry ingredients (flour, baking powder, soda, salt and the zest). Set aside.
Generously grease and flour the bundt pan. Set aside.
In a large mixing bowl of a stand mixer, beat together butter and sugar until light and fluffy.
Add eggs, one at a time, beating well after each addition.
Add vanilla, lemon extract and beat well again.
With the mixer on low speed, add the dry ingredients alternating with buttermilk. Increase the speed to medium and beat for 2 minutes.
Pour the batter into prepared pan.
Bake for 40 minutes, or until the toothpick inserted in the center comes out clean.
Cool the cake for 2 minutes in the pan. Place a cake plate over the top of the pan and carefully flip it upside down. If the cake won't release right away, tap the pan gently until it does. Cool cake completely before glazing.
Place powdered sugar in a medium mixing bowl. Add a tablespoon of lemon juice and whisk in, adding another tablespoon. You want thick but drizzling consistency. You may need to add more juice. I ended up adding another 1,5 tsp.
Glaze the cooled cake.
Store remaining cake in a closed container for up to 4 days.
Notes
If using sour milk: place 1 tablespoon of white vinegar in a measuring cup and fill with enough milk to make 1 cup. Stir few times and let sit for 2 to 3 minutes.
Please note, that the nutrition value can vary depending on what product you use. The information below is an estimate. Always use calorie counter you are familiar with.