Step 1

Line two sheet pans with parchment paper. I used a 1½-inch round cookie cutter to draw circles on the parchment paper and flip over the paper (drawing side down). Prepare a pastry bag with a round tip. I used Wilton 2A.

Step 2

Using a food processor, pulse the powdered sugar, almond flour, espresso powder and pumpkin pie spice. Sift several times until there is less than 2 tablespoons of almond bits left. Add these to the mixture.

Step 3

In the bowl of an electric mixer with the whisk attachment, combine the egg whites, cream of tartar, and sugar and salt. Whip on medium-high speed until stiff peaks form, about 5-7 minutes. Add in the drops of food coloring if using and mix until combined

Step 4

Add the dry ingredients to the meringue and fold with a rubber spatula. Gently fold to deflate the meringue by pressing against the side of the bowl and scooping from the bottom until batter is smooth and shiny; about 20-25 folds. To check consistency, drop a spoonful of batter and it should have a peak that quickly relaxes back into the batter. Start checking the batter around 18-20 folds.

Step 5

Transfer batter into pastry bag and pipe the batter into the pre-traced circles on the baking sheet. Tap baking sheet hard on a counter to release any air bubbles trapped in the batter.

Step 6

Let shells sit on a counter for at least 30 minutes and up to 2 hours to dry. When you touch the shells, they should not be sticky.

Step 7

Preheat oven to 300 degrees F. Bake for 15-20 minutes or until shells hardens, rotating cookie sheets halfway through baking time. You should be able to peel off the macaron from the parchment. Cool completely on cookie sheets before peeling from the parchment.

Step 8

In the bowl of an electric mixer, whip the egg whites until soft peaks form. Gradually add the sugar and espresso powder to the egg whites with the mixer on medium speed. Whip until stiff peaks form. Fill macaron shells with marshmallow fluff.