Preheat your oven to 225°F (110°C) and prepare a baking sheet lined with parchment paper.

In a mixing bowl, beat room temperature egg whites on medium speed until frothy and soft peaks form (2-3 minutes).

Gradually add cream of tartar and a pinch of salt, beating until the mixture holds soft peaks (1-2 minutes).

Slowly incorporate sugar, 1 tablespoon at a time, while mixing for 3-4 minutes, then fold in Jello powder until stiff peaks and glossy texture are achieved.

Fill a piping bag fitted with the #1M tip with the meringue and pipe small rosettes on the baking sheet.

Bake for 1 hour, then turn off the oven and let the cookies cool inside for another hour without opening the door.

After cooling, check cookies for dryness and remove if they feel light and crisp.