Preheat the oven to 350°F (175°C).

Grease and flour two 8-inch round cake pans.

In a bowl, whisk together the flour, baking powder, baking soda, and salt.

In a separate bowl, beat the butter and sugar with an electric mixer until light and fluffy.

Add the eggs one at a time, mixing well after each addition, then stir in the limoncello and lemon zest.

Alternately add the dry ingredients and buttermilk to the butter mixture, beginning and ending with the dry ingredients; mix until just combined.

Divide the batter evenly between the prepared pans and bake for 30–35 minutes, or until a toothpick inserted into the center comes out clean.

Let the cakes cool in the pans for 10 minutes, then transfer them to a cooling rack to cool completely before serving or frosting.