Spray the inside of a 3-quart glass or metal mixing bowl with cooking oil. Line the bowl with plastic wrap, leaving some overhang, then fill the bowl with scoops of the ice cream, alternating scoop sizes. Smooth the top of the ice cream with a rubber spatula, then press a piece of plastic wrap to top of the ice cream. Freeze until completely firm, 1-2 hours.
48 ounces ice cream
Remove the plastic wrap from the top of the frozen ice cream. Cut the pound cake into ½-inch-thick slices. Arrange the slices over the ice cream, completely covering it and trimming as needed. Cover with plastic wrap and freeze until firm, at least 2 hours.
1 loaf pound cake
When ready to serve, line a baking sheet with parchment. Set aside.
Place the egg whites and cream of tartar in a large mixing bowl. Use a hand mixer to whip on medium-high speed until foamy, about 2 minutes. Gradually beat in the sugar on high speed until the whites are glossy and form stiff peaks.
6 large egg whites, ⅛ teaspoon cream of tartar, 1 cup granulated sugar
Remove the top layer of plastic wrap from the cake, then invert it onto the prepared baking sheet and discard the plastic wrap.
Cover the ice cream completely with a thick layer of the meringue, using a spoon or spatula to form decorative swirls and peaks.
Broil on high just until the meringue begins to brown, about 3-4 minutes. You can also toast the meringue with a kitchen torch so the peaks are lightly browned. Transfer the cake to a serving plate, slice, and serve immediately.