Step 1

Preheat the oven to 350 F and grease and flour a 9x13 baking pan.

Step 2

In a bowl, beat butter for about one minute and then add sugar. Beat for another 1 -2 two minutes, until light.

Step 3

Add egg whites one at a time, beating well after each addition. Add vanilla and mix until combined.

Step 4

Sift flour, baking soda, baking powder, salt together.

Step 5

On the low speed of your electric mixer alternate adding the flour mixture and buttermilk starting and ending with the flour mixture. Mix until just combined.

Step 6

Pour the batter into the prepared baking pan and spread out evenly. Bake for about 25-30 minutes, until the toothpick inserted in the center of the pan comes out clean.

Step 7

Cool completely before frosting.

Step 8

Place the egg yolks and sugar in the top of a double boiler or a large heat proof bowl over a saucepan that has an inch or two half of water, making a kind of double boiler.

Step 9

With a wire whisk or with the whisk attachment of a hand mixer beat the egg yolks with the sugar until they are completely combined and the mixture has a glossy appearance.

Step 10

Turn on the flame, moderately high until the water boils, then reduce the heat to a simmer and keep whisking. Make sure the bottom of the double boiler or bowl does NOT touch the water. As the water heats the egg mixture it will begin to thicken. As it thickens it will grow in volume. Keep whisking. This takes a little patience but it is well worth the effort. Your zabaglione will be done when it is thick, frothy and holds ribbons form as you whisk it. The temperature reaches 145 to 150 degrees F, on an instant-read thermometer.

Step 11

Take the zabaglione off the heat and continue to whisk. Add the Mascarpone to the whipped yolks and beat until combined. Add the Amaretto liqueur. Cover with plastic wrap and let cool completely.

Step 12

In a separate bowl, that has been chilled along with the beaters, whip the cream to stiff peaks taking care NOT to overbeat and make butter.

Step 13

Gently fold in the whipped cream into the zabaglione mixture and set aside.

Step 14

Put the espresso in a food safe spray bottle. Spray the white cake with the espresso making sure you don't oversaturate. The 1/3 cup of espresso should be just right. If you don't have a spray bottle you can do it by hand-- be sure you don't get too much in one spot.

Step 15

Spread the Zabaglione Cream evenly over the top of the espresso-sprayed cake.

Step 16

Dust the top with cocoa powder and garnish with crushed chocolate chips.