Place the ice cream in the fridge for 20 to 30 minutes or soft enough to very easily scoop, but not runny.
While the ice cream softens, very lightly coat an 8- to 9-inch-wide bowl with oil. Line with plastic wrap, leaving several inches of overhang around the edges.
Slice the pound cake into ½-inch-thick pieces.
When the ice cream is soft, place alternating scoops of the various ice cream flavors in the lined bowl, reserving half of the 1.5-quart flavor. Press a piece of plastic wrap to the top of the ice cream scoops and gently press down to fill in any gaps between the scoops. Smooth out the top. Freeze for 15 to 20 minutes or until the top is mostly firm. Return the remaining ice cream to the fridge while the bowl freezes.
Once mostly firm, remove the plastic and spread the remaining ice cream over the mixed scoops. Place pound cake slices on top, making sure they fit snugly together. Cut some of the pound cake to fill in any gaps, as needed. (There will probably be some cake leftover.) Fold the excess plastic wrap up over the cake to cover and freeze until solid, about 2 to 4 hours or up to 1 week.
For the Meringue:
When ready to serve, place the egg whites and cream of tartar in the bowl of a stand mixer with the whip attachment. Beat on medium speed until frothy and doubled in volume, about 2 minutes. Very slowly add in the sugar while beating. Once added, continue beating until stiff and glossy, about 6 more minutes.
For the Assembly:
Remove the bowl of ice cream from the freezer and unwrap the bottom. Place a large plate on top and flip to invert, using the excess parchment to help release the ice cream from the bowl. Once inverted, carefully remove the plastic from the ice cream.
Spread or pipe the meringue all over the ice cream, making sure that it is completely covered and touching the plate, creating a seal. Using a kitchen torch, brown the meringue. Serve immediately. Loosely cover any leftovers with plastic wrap and freeze for up to 1 week.
Save your fresh eggs for another recipe. Older eggs whip up higher and fluffier.
Even a touch of yolk in the egg whites will make whipping up the meringue difficult. I recommend separating the egg yolks and egg whites one at a time in a separate bowl to add to the mixer, so if you break one yolk, you don’t ruin the whole batch.
Eggs separate easier while cold, but egg whites whip up better at room temperature. After separating the eggs, allow them to sit out to bring them down to room temperature.
Baked Alaska will still be frozen and hard when you cut into it. Be careful when cutting down, as you’ll have to push down hard.
Change things up by using brownies for the base instead of a pound cake.
You can make a batch of Italian Meringue instead of the French for an even silkier covering.
Don’t try to rush the process. The ice cream needs to be rock solid before you spread the meringue on top. If the ice cream isn’t fully frozen, the meringue will start sliding off.