Preheat your oven to 350°F (175°C) and prepare two 9-inch round baking pans by greasing them with butter and lining with parchment paper.

In a large mixing bowl, cream together 1 cup of softened butter and 2 cups of granulated sugar for about 5-7 minutes until light and fluffy.

Add 4 large eggs, one at a time, mixing well after each addition. Fold in the zest from 2 lemons and 1/4 cup of lemon juice.

In a separate bowl, whisk together 1 cup of sour cream and 1/2 cup of milk until smooth. Combine flour, baking powder, baking soda, and salt in another bowl.

Gradually alternate adding the dry and wet mixtures into the creamed mixture, stirring until just combined.

Divide the batter evenly between prepared pans and bake for 24-28 minutes, or until a toothpick comes out clean.

Allow the cakes to cool in pans for 10 minutes, then transfer to wire racks to cool completely.

Prepare lemon syrup by combining 1/2 cup of lemon juice with 1/2 cup of sugar. Boil and simmer until reduced by half.

Beat together cream cheese and butter, gradually adding confectioners' sugar, lemon juice, and salt until fluffy.

Once cooled, slice each cake layer in half to create four layers total. Brush with lemon syrup.

Assemble by layering cakes with frosting in between, finishing with frosting on top and sides.