Preheat the oven to 200 degrees Fahrenheit and line two baking sheets with parchment paper.

Add the egg whites and cream of tartar to the bowl of a stand mixer. Beat with the whisk attachment on medium speed until frothy. Ensure your bowl and whisk attachment are clean, dry, and free of any residue before beginning.

Gradually add the sugar, 1 tablespoon at a time, while continuing to beat. Once all the sugar is added, increase to high speed and beat until stiff, glossy peaks form and the sugar is fully dissolved.

Beat in the vanilla extract just until combined.

Scoop about ⅓ cup of the meringue into a small bowl and set it aside. Tint this portion with green gel food coloring and stir until evenly colored.

Add orange gel food coloring to the remaining meringue in the mixer bowl and mix until evenly tinted, adjusting the amount as needed.

Transfer the orange meringue to a piping bag fitted with a large round or star tip. (I used a Wilton #8 B star tip) Pipe small pumpkin shapes onto the prepared baking sheets, spacing them about 1 inch apart.

Transfer the green meringue to a small piping bag fitted with a round tip (or use a zip-top bag with the corner snipped) and pipe small stems on top of each pumpkin.

Bake for 45 minutes, then turn off the oven and let the meringues cool inside the oven for at least 2 hours or preferably overnight. Do not open the oven door during this time.

Once fully cooled, store in an airtight container at room temperature.