Preheat the oven to 350 F degrees.
Prepare a 9×5 loaf pan with baking spray and parchment paper.
In a medium bowl whisk together the flour, baking powder, baking soda, and salt. Set aside.
In a mixer add the sugar and the lemon zest and mix for about 4 minutes. The sugar will get a very lemon fragrance to it. The sugar will clump together like wet sand.
Add the butter and cream for 1 minute, until fluffy.
Add one egg at a time until well combined.
Turn the mixer on low and slowly add the flour mixture.
While the mixer is on low add the 2 tablespoons of lemon juice and the sour cream. The batter should be a little thick.
Pour the batter into the pan and bake for 50-60 minutes. If the loaf is brown on top, insert a toothpick to see if the cake is ready. It should come out clean. I have been using my cake tester for this cause my loaves would sometimes be raw at the bottom.
Once the loaf has cooled poke some holes in the top using a cake tester, fork, skewer, almost anything, and pour the remaining 2 tablespoons of lemon juice over top.