7 hours 20 minutestotal time
1 (1.5 quart) carton or 3 pints chocolate ice cream
1 (1.5 quart) carton or 3 pints cherry or strawberry ice cream
1 (12-ounce) store-bought loaf pound cake or a homemade loaf pound cake, cut into 1/2-inch-thick slices
6 large egg whites, at room temperature
1/8 teaspoon cream of tartar
1/4 teaspoon vanilla extract
Pinch of kosher salt (such as Diamond Crystal)
1 cup granulated sugar
Line the inside of a 9-inch (3-quart) mixing bowl with plastic wrap, leaving a few inches of overhang on all sides. Let the chocolate ice cream soften at room temperature for 15 minutes, then spoon it into the prepared bowl. Use a rigid spatula or wooden spoon to spread the ice cream into an even layer at the bottom of the bowl, packing it slightly so it’s dense. Freeze until the ice cream is firm to the touch, at least 1 hour.
Remove the cherry ice cream from the freezer and soften at room temperature for 15 minutes, then spoon it onto the refrozen chocolate ice cream. Spread it into an even layer, leaving ½-inch at the top of the bowl. (You may have some ice cream left in the container.) Working quickly, arrange the pound cake slices on top, cutting them to fit so the entire surface of the ice cream is covered. Fold the overhanging plastic wrap over the cake and freeze for at least 3 hours, and up to 72 hours.
At least 3 hours before you plan to serve the baked Alaska, make the meringue: Place the egg whites and cream of tartar in the bowl of a stand mixer fitted with the whisk attachment. (Alternatively, you could also use a hand mixer.) Whisk the egg whites on medium-high until frothy and doubled in volume, about 1 minute. Add the vanilla and salt, and then, with the mixer running, gradually pour in the sugar. Increase the speed to high and whisk until stiff peaks form.
Line a sheet pan with parchment paper. Pour about 1 inch of warm water into a very large mixing bowl (larger than the bowl used for the baked Alaska.) Place the cake bowl in the water for 15 seconds, then lift the plastic to release it and invert the ice cream cake onto the sheet pan. Remove and discard the plastic wrap.
Using a spatula or a piping bag, spoon or pipe the meringue onto the baked Alaska to create spiky peaks, covering the sides entirely. (Be sure not to leave any spots exposed.) Freeze uncovered for at least 2 hours, until the meringue is firm to the touch.
Heat the oven to 450 degrees and place a rack in the middle. With the cake still on the sheet pan, bake for 3 to 5 minutes, watching carefully, until parts of the meringue are lightly browned. (You can also use a kitchen blowtorch for this step.) Use two large spatulas to transfer the baked Alaska to a serving platter, then set it on the counter for up to 10 minutes to defrost slightly for easier slicing. Slice the baked Alaska into wedges using a large, sharp knife, and wiping the blade in between cuts for clean slices. Use a pie server or spatula to remove the slices, and serve immediately.
7 hours 20 minutestotal time