To Make the Batter with a Stand Mixer:

1. Preheat oven to 325°F.  It’s highly recommended to use an oven thermometer for this recipe, since proper oven temperature will impact the outcome of your cake.  Take out three 8” cake pans and parchment paper and set them aside.
2. Combine the flour, baking soda, and salt in a medium bowl.
3. Sift the flour mixture into another medium bowl.  Set aside.
4. Place the room temperature butter in the bowl of your stand mixer.  Mix on low speed until smooth.  (30 seconds)
5. Slowly add the granulated sugar and mix on medium speed until the mixture is light and fluffy.  (5-10 minutes)
6. Add eggs, one at a time, mixing for at least 45 seconds after each addition.  Scrape the sides and bottom of the bowl as needed.  (5 minutes)
7. Add vanilla extract, limoncello and lemon zest and mix on medium speed until thoroughly combined.  (1 minute)
8. Add half of the flour mixture and mix on low speed until combined.  (30-45 seconds)
9. With the mixer on low speed, add the buttermilk and mix on low speed until combined.  (~1 minute).
10. Add the second half of the flour mixture and mix on low speed until combined.  (~1 minute)
11. Using a rubber spatula, fully scrape the sides and bottom of the mixing bowl.  Then, stir the batter until it is smooth and consistent.  Make sure to fully scrape the bottom of the bowl during this step!
12. Prepare three 8” cake pans.  Place parchment round at the bottom of the cake pan to help prevent sticking.
13. Fill cake pans evenly.  I use a digital kitchen scale, and my cake pans each hold roughly 400-420 g of cake batter.
14. Level out the cake batter with a spatula.  Tap the cake pans on the countertop to help prevent large bubbles in your cakes.

To Make the Batter with a Hand Mixer:

1. Preheat oven to 325°F.  It’s highly recommended to use an oven thermometer for this recipe, since proper oven temperature will impact the outcome of your cake.
2. Combine the flour, baking soda, and salt in a medium bowl.
3. Sift the flour mixture into another medium bowl.  Set aside.
4. Place the room temperature butter in a large mixing bowl.  Mix on low speed until smooth.  (30-45 seconds)
5. Slowly add the granulated sugar in two additions and mix on medium speed until the mixture is light and fluffy.  (7-12 minutes)
6. Add the eggs, one at a time, mixing for at least 45-60 seconds after each addition.  Scrape the sides and bottom of the bowl as needed.   (4 minutes)
7. Add vanilla extract, limoncello and lemon zest and mix until thoroughly combined.  (1 minute)
8. Add half of the flour mixture and mix on low speed until combined.  (30-45 seconds)
9. With the mixer on low speed, add all of the buttermilk and mix on low speed until combined.  (~1 minute).
10. Add the second half of the flour mixture and mix on low speed until combined.  (~1 minute)
11. Using a rubber spatula, fully scrape the sides and bottom of the mixing bowl.  Then, stir the batter until it is smooth and consistent.  Make sure to fully scrape the bottom of the bowl during this step!
12. Prepare the three 8” cake pans.  Place parchment round at the bottom of the cake pan to help prevent sticking.
13. Fill cake pans evenly.  I use a digital kitchen scale, and my cake pans each hold roughly 400-420 g of cake batter.
14. Level out the cake batter with a spatula.  Tap the cake pans on the countertop to help prevent large bubbles in your cakes.

To Bake the Cake:

1. Bake the cakes at a true 325°F for 30-35 minutes, or until an instant read thermometer reads 210°F.
2. Allow the cakes to rest for ten minutes, and then turn out on a cooling rack to cool completely.

To Make the Simple Syrup:

1. Combine sugar, water, and salt in a small saucepan and bring to a boil.
2. Reduce to medium heat and add limoncello.
3. Stir occasionally until the sugar is completely dissolved.
4. Remove the simple syrup from the heat and allow to cool completely.
5. Place the simple syrup in a small bowl or squeeze bottle.

To Make the Swiss Meringue Buttercream:

1. Bring 3” of water to a low boil in a large (3 qt.) sauce pan.  Reduce to a simmer.
2. Cut cold butter into 1-tbsp pieces and set aside.
3. Carefully separate 8 eggs, placing the whites in a very clean, nonreactive metal bowl (either a stand mixer or large stainless steel bowl).  Add sugar and stir to combine.
4. Place metal bowl over the top of the sauce pan while the water is simmering.  Whisk the egg white mixture over the sauce pan until all of the sugar is completely dissolved.  (~3 minutes)
5. Remove the metal bowl from the stove.  Using the whisk attachment on either your hand mixer or your stand mixer, whisk the mixture on lowest speed until it is nearly opaque.  (~1-2 minutes)
6. Increase the mixer to medium speed until the mixture begins to look light and fluffy.  (~4 minutes for stand mixer; ~5-6 minutes for hand mixer)
7. Increase the mixer to highest speed until the meringue has reached nearly stiff peaks.  The meringue should be lukewarm before moving onto the next step.  This step could take anywhere from 10-15 minutes.  If the meringue doesn’t form nearly stiff peaks after this time, place in the refrigerator for 15 minutes and whip again.
8. With the mixer on medium speed, add the butter, one tablespoon at a time.  Make sure that each tablespoon of butter is fully incorporated before adding the next tablespoon. (8-10 minutes)
9. It is important to note that the Swiss Meringue Buttercream will begin to look more liquid while you add the butter.  Keep going!  It will firm back up as you get toward the end of the butter additions!
10. After adding the last tablespoon of butter, you can switch to the paddle attachment on your mixer if you’d prefer a smoother buttercream.  Mix the buttercream on medium speed until it reaches a firm texture.  This generally takes between 2-6 minutes, but the temperature and humidity of your kitchen will be the big determining factor.  Watch your mixer carefully to make sure that the buttercream doesn’t curdle.
11. If the buttercream won’t firm up, place the bowl into a refrigerator for no more than 20 minutes.  Mix again on medium speed until it reaches a firm texture.
12. Add salt, limoncello and vanilla and mix until it again reaches a firm texture.
13. This buttercream is not stiff like American Buttercream, but it should be stiff enough to pipe (if desired).

To Build the Cake:

1. Place a 10” cake round on a turntable or a cake stand.
2. Place a dollop of Swiss Meringue Buttercream on the round to secure the bottom cake.
3. The cakes might be slightly domed from baking.  If they are domed, gently cut off the domes to make them level.  (I cooled these cakes with the dome side down, which fixed this issue for me.)
4. Use either a spoon or a squirt bottle to add simple syrup to the top of each layer.
5. Place the second layer on top  of the first layer.  Add buttercream to the middle layer and spread.
6. Invert the final layer and place on top of the other two layers.  Press down gently and double check to make sure the cake is level.
7. Using an offset spatula, spread the buttercream over the entire cake.

To Store:

This cake can be left on the countertop for two days, or refrigerated for up to a week.  Allow to come to room temperature before serving.