01 -
Preheat oven to 225°F and line a baking sheet with parchment paper.
02 -
In a clean mixing bowl, whisk egg whites on medium speed until foamy, about 2 minutes.
03 -
Add cream of tartar and continue whisking until soft peaks form.
04 -
Increase mixer to high speed and gradually add granulated sugar one tablespoon at a time, whipping until stiff and glossy peaks form, 8 to 10 minutes in total.
05 -
Gently fold in vanilla extract and green gel food coloring with a spatula until just combined.
06 -
Transfer the meringue mixture to a piping bag fitted with a large star tip. Pipe cone-shaped trees by starting with a broad base and spiraling upward in smaller circles to form a peak.
07 -
Bake for 1 hour and 30 minutes without opening the oven door, ensuring meringues are completely dry and crisp.
08 -
Turn off the oven, prop the door open slightly, and allow meringues to cool inside for 30 minutes before removing from the oven.
09 -
Garnish cooled meringue trees with sprinkles as desired.