First, prepare the ice cream dome. Line a medium bowl very well with plastic wrap (the widest part of the bowl should not exceed 8 inches).

Spoon the pint of softened chocolate gelato into the bowl, then place in freezer for about 30 minutes until solid. Repeat with the hazelnut and stracciatella gelato, being sure to freeze in-between to keep the layers separate. Cover tightly with the plastic wrap, and freeze until completely solid (at least overnight).

Next, make the chocolate cake. Preheat oven to 350F, line the bottom of an 8" cake pan with parchment, and spray with baking spray.

In medium bowl, whisk together flour, cocoa, baking powder, baking soda, and salt. In a measuring cup, mix together milk and vanilla.

In a stand mixer, at low speed, beat butter and sugar till blended. Increase speed to high and beat for 2 minutes. Reduce speed to medium-low and add egg and yolk, beating well. Mix in ¼ cup of chocolate hazelnut spread.

With mixer at low speed, alternatively add the flour mixture and the milk mixture, starting and finishing with the flour. Beat until batter is smooth, occasionally scraping bowl with a spatula.

Pour batter into prepared pan and spread evenly.

Bake until toothpick inserted in center comes out clean, 25-30 minutes.

Remove from pan and let cool completely.

When ready to assemble, place the cake on an 8" cardboard cake plate. Spread the extra ¼ cup of chocolate hazelnut spread on top.

Carefully unwrap the prepared ice cream dome, and place on top of the cake. If the cake is wider than the ice cream, use a sharp knife and carefully cut the excess off.

Place the ice cream cake in the freezer while you prepare the meringue.

Place the egg whites and sugar in a heat-proof bowl (ideally your stand mixer bowl). Place over a small pot of water, and whisk often until the mixture is smooth and slightly warm to the touch. If you rub the mixture between your fingertips, it should be totally smooth with no sugar granules.

Transfer the bowl to a stand mixer with the whisk attachment, sprinkle in the cream of tartar, and beat on high until fluffy meringue forms. It should hold stiff peaks, meaning if you dip the whisk in the meringue and flip it upside down, it should hold its curl shape.

Remove ice cream cake from the freezer, and spread the meringue evenly all over the surface.

Using a kitchen torch, carefully broil the meringue to give it a toasted look.

If you do not have a kitchen torch, you can broil the baked Alaska at 500F for 2-3 minutes. Be very careful! Make sure you put the cake back in the freezer until the oven is ready (the cold does not affect the meringue).

Serve immediately, and store leftovers in the freezer.