Preheat oven to 350 degrees F. In a medium bowl, sift together flour, baking soda, and kosher salt three times.
3 (375 g) cups Cake flour, ½ teaspoon Baking soda, ½ teaspoon Kosher Salt
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugar at medium low speed until combined. Increase speed to medium and continue to beat until pale and fluffy, about 5 minutes, stopping halfway to scrape the sides of the bowl.
1 (227 g) cup Unsalted butter, 2 ½ (500 g) cups Granulated sugar
Add the first 3 eggs one a time on low speed then increase to medium mixing until each egg is incorporated. After adding the first 3 eggs, stop the mixer and scrape the sides and bottom of the bowl. Add the remaining 3 eggs, one at a time mixing until each egg is incorporated. Scrape the sides and bottom of the bowl after adding the last egg.
6 large Eggs
With the mixer on low speed gradually add the flour mixture alternately with the sour cream mixture, beginning with flour mixture and ending with the sour cream. Beat until just combined after each addition, stopping to scrape the sides of the bowl.
1 (240 g) cup Sour cream
Add the lemon juice, lemon zest, and lemon extract. Mix until all of the ingredients are just combined, being careful not to over mix
2 tablespoons Lemon zest, 2 tablespoons Lemon juice, 1 ½ teaspoon Lemon extract
Spray a 12 cup bundt pan with nonstick baking spray. Using a fine pastry brush, spread the baking spray to coat the pan making sure to get into all the nooks and crannies. Transfer the cake batter to the prepared pan and smooth the top with an offset spatula. Firmly tap the pan on the counter to release any air bubbles then bake for 55 to 65 minutes until a toothpick or cake tester comes out clean with a few moist crumbs. Remove the cake from the oven and allow it to cool in the pan on a wire rack for 10 minutes. Invert cake onto wire rack to cool completely, about 2 hours.