Line an 8 inch square baking pan with a single large sheet of parchment paper. Make sure your parchment paper covers the entire inside of the pan and has enough extra above the pan that you can use as handles to lift the cake out later.

Add lemonade to a medium saucepan. Sprinkle gelatin on top. Use a whisk to fully mix the gelatin in until no clumps remain. Bring your mixture to medium heat on the stove. Let the mixture get hot but don't let it reach a simmer. Whisk a few times once the mixture is hot to ensure that the gelatin is fully dissolved. Remove mixture from heat.

Pour mixture into the bowl of a stand mixer. Let your mixture cool to room temperature (about 15-20 minutes). Once the mixture has cooled, use the wire whisk attachment and beat on highest speed for about 15 minutes. The mixture should gradually thicken, turn white and eventually should looked like meringue. When you stop your mixer, your wire whisk should be able to hold a soft peak. Even if your mixture has not reached meringue consistency after 15 minutes, stop your mixer. Let the mixture stand for 1 minute and then beat for about another 5 minutes or until it can hold a soft peak. See post for photo of what the mixture should look like when it is ready. If you use store bought lemonade you will need less mixing time than if you use homemade lemonade. See notes for more details.

Pour mixture into your prepared pan. Use a spatula to spread it evenly across and smooth the surface. Place into fridge until set. This should take abotu 30-60 minutes. To check if cake is set, press lightly on the surface. The cake should not be wet or liquid and it should feel springy and bounce back.

Keep the cake in the fridge until ready to serve. Before serving, you can decorate the cake with whipped cream frosting or other frosting. Slice cake with a very large and sharp knife. The cake is best served chilled. Store any uneaten cake in the fridge.