Preheat the oven to 350 degrees F and line a 9 in loaf pan with parchment paper or spray with a non-stick cooking spray.
In a large bowl, cream together the butter, sour cream and sugar with a hand held or stand up mixer until the mixture is light and fluffy.
Slowly add in the eggs into the mixture one at a time mixing in between each egg. Then stir in the lemon extract.
In a separate bowl, combine the flour, salt, baking soda and baking powder.
Gradually add the dry ingredients into the wet ingredients until just combined. Then gently mix in the lemon zest.
Pour the mixture into the loaf pan and bake uncovered for 50-60 minutes until a toothpick inserted into the middle of the loaf comes out clean.
Let the cake cool for 10-15 minutes in the pan and then move to a wire rack to cool completely.
While the cake is cooling, prepare the glaze by whisking together the powdered sugar, milk and lemon juice in a medium size bowl. Add in more powdered sugar or milk as needed for the desired consistency.
Once the cake has cooled, pour the glaze over the top, slice and enjoy!
Notes
The lemon Extract is needed for that strong lemon flavor that is similar to the Starbucks cake.