Preheat the oven to 350 degrees Fahrenheit. Line the bottom of 2 round (9 inccake pans with parchment paper.

Separate the eggs, putting the whites in one bowl and the yolks in another.

Beat the whites using a whisk attachment on a standing mixer or a hand held mixer until foamy. Gradually pour in half of the sugar. Mix the whites on high speed until stiff peaks form. Set aside.

In the other bowl with the yolks, add the remaining sugar and use the same whisk attachment to beat the yolks until they are pale and fluffy.

Combine the milk, melted butter, vanilla extract and lemon zest in a bowl or cup. Set aside.

Using a rubber spatula, fold the egg whites into the egg yolks, being careful not to deflate the batter as much as possible.

Sift the flour, baking powder, and salt over the folded eggs and gently fold in the batter.

When there are still some remaining streaks of flour, pour in the milk and butter mixture into the batter by the side of the bowl. Continue gently folding until evenly distributed.

Divide the batter in half, pouring into the prepared cake pans.

Bake in the preheated oven until they are golden and a toothpick inserted into the center of the cake comes out clean, 20-25 minutes.

Cool on a wire rack.

Meanwhile, prepare the limoncello syrup and the frosting.

Make a simple sugar by heating the sugar and water in a small pot until sugar dissolves and add the limoncello. Set aside to cool.

In a standing mixer with a paddle attachment or using a hand mixer, mix the cream cheese and powdered sugar until evenly mixed, smooth and fluffy. Add the lemon zest, vanilla extract and limoncello.

Add the mascarpone cheese. You can just fold in the mascarpone cheese with a rubber spatula, since it's soft enough or mix with the mixer just until combined, about 30 seconds.

In a separate bowl, whip the heavy cream until fluffy and stiff peaks form. You can do this by hand using a whisk or use a hand held mixer or a standing mixer.

Using a rubber spatula, fold in the whipped cream into the frosting until evenly mixed.

Cut each cake in half horizontally.

Using a serrated knife, make a small cut all around the outside of the cake. This will keep your knife on the same level as you are cutting across. Continue cutting deeper into the cake until you have cut all the way through.

Another trick I use when decorating cakes is to line the serving plate all around the edge with aluminum foil so that the edge of the cake is overlapping the aluminum foil by about 1/2 inch. This will catch all the drips and crumbs, leaving your serving plate neat and clean. When you're done decorating just carefully pull the aluminum foil out.

Using a pastry brush, brush the top and bottom of each layer with the limoncello syrup.

Put a dollop of frosting in the center of the cake plate, which will help to hold the cake in place. Place the first cake layer in the center of the cake plate and generously spread the cake layer with frosting, all the way to the edges.

Place the second cake layer on top of the frosted cake layer. Spread the lemon curd evenly over the surface of the cake, all the way to the edges. You can use more or less lemon curd, depending on how sweet and "lemony" you want the cake to be.

Place the third cake layer on top of the lemon curd layer and generously spread the cake layer with frosting, all the way to the edges.

Top with the last layer and this time frost the sides and the top of the cake. Carefully pull out the aluminum foil from underneath the edges of the cake and discard.

You will have enough frosting left over to pipe a border all the way around the cake too. I piped a border all the way around the edges of the cake and added a few swirls in the center too. I used my favorite Wilton 1M piping tip.

I also grated white chocolate on top of the cake as well as lemon zest and a thin lemon slice in the center of the cake.

The cake should be chilled in the refrigerator for at least 2-4 hours before serving, or overnight. The cake can be made 2 days in advance, completely assembled and stored in the refrigerator, covered.

Before serving, let the cake stand at room temperature for about 30 minutes, for the best taste and texture.