Preheat Oven: Preheat your oven to 350°F (or 325°F if using a convection oven). Grease a 12-cup Bundt pan with butter. Use about 1-2 tablespoons of softened butter. After greasing, dust with flour to ensure it covers all the details if your pan has intricate patterns.
Prepare Dry Ingredients: In a medium bowl, whisk together the flour, salt, baking powder, and baking soda. Set aside.
Make Lemon Sugar: Zest the lemons and rub the zest with the sugar in a large bowl using your fingers until fragrant. This helps release the lemon's natural oils.
Cream Butter and Sugar: In a large mixing bowl, beat the butter on medium speed for 2 minutes. Add the lemon sugar and beat again until fluffy and light, about 2 minutes.
Add Eggs: Beat in the eggs one at a time, ensuring each is fully mixed before adding the next.
Add Wet Ingredients: Mix in the sour cream and lemon juice on low speed until combined.
Combine Dry and Wet: Add half of the flour mixture and mix on low until just combined. Then, add the milk and mix. Finally, add the remaining flour mixture and mix until just incorporated.
Fill Pan and Bake: Pour the batter into the prepared Bundt pan and spread it evenly with a spatula. Bake in the preheated oven for 45-65 minutes, checking at the 45-minute mark. If the cake is browning too quickly on top but isn't done inside, cover with aluminum foil.
Check Doneness: The cake is done when it no longer jiggles and a toothpick inserted comes out clean. Let the cake cool in the pan for 5 minutes.