To make the green decorative vines, make two batches of macarons batter. Begin by making your pumpkin (orange) batter, and once piped, make a batch in the same way but replacing the orange food color with green!
In the bowl of a stand mixer fitted with the whisk attachment, or with a hand-held mixer, beat the egg whites with the cream of tartar and pinch of salt until they reach the soft peak stage. Slowly add the granulated sugar and beat on high speed until very stiff.
Sift half of the powdered sugar, almond flour, cinnamon and ginger over the meringue and fold until the mixture is still very stiff but most of the dry ingredients look incorporated. Fold in the remaining dry ingredients and continue folding until the mixture looks less like a dough and more like a thick batter that forms a neat ribbon as it falls.
To pipe pumpkins:Place the batter in a piping bag fitted with a round tip (we use Ateco 804). Using half the batter, pipe 10 wheel-like circles and a line from the top of the circle down to the bottom. Let these half-piped pumpkins dry for 5 minutes. Fill in the holes, making a rounded half-circle from the top of the pumpkin down to the bottom to and repeat on the other side. You should have 10 circles that look like they have bumpy pumpkin segments! If making vines, make the second batter and color it green. Use a smaller round tip to first pipe a stem just above, but touching, the pumpkins. Pipe vines over the pumpkins, if desired. Let the cookies dry until you can touch them without leaving batter on your finger (about 30-45 minutes).
Preheat your oven to 350F. Once preheated, place the cookie sheets in the oven (one at a time for a still oven or both if you have convection) and turn the heat down to 300F. Bake for about 10-15 minutes, or until they just feel firm and no longer sink when you press down on them from the tops. Wait at least 10 minutes to allow the cookies to set as they cool before removing them from the parchment paper.