Line an 8" round mixing bowl with plastic wrap. 

Pack the softened ice cream into the prepared bowl, then flatten the top and cover with more wrap. 

Freeze until firm, at least 8 hours.

Beat egg whites, sugar, cream of tartar, and salt with the standing mixer until stiff peaks form.

Line a baking sheet with parchment paper and place prepared cake in the center. Remove is cream from the freezer and unwrap, discarding the plastic wrap. Place ice cream on top of cake. 

Spread the meringue over the top of the ice cream and cake, swirling if desired. 

Freeze for 2 hours. 

Preheat oven to 425°F. 

Bake cake on the lowest oven shelf until meringue is light brown, approximately 8-10 minutes.