Line 3 large baking sheets with parchment paper and set aside.

In a medium bowl, whisk together the almond meal, powdered sugar, and pumpkin pie spice until combined.

In the bowl of a stand mixer fitted with the whisk attachment, beat the egg whites on medium speed until frothy.

Gradually add the granulated sugar, 1 tablespoon at a time, and continue beating until soft peaks form and the tips just curl. Beat in the vanilla and salt.

Gently fold the almond mixture and food coloring (if using) into the whipped egg whites until the batter is smooth and thick but still slightly flows when lifted.

Transfer the batter to a piping bag fitted with a large round tip. Pipe 1½-inch rounds about 1 inch apart on the prepared baking sheets.

Tap the baking sheets lightly on the counter to release any air bubbles, then let them rest at room temperature for about 30 minutes, until the tops look glossy and dry to the touch.

Preheat the oven to 350°F (175°C). Bake the macaroons for 9–10 minutes, or until just set and lightly golden.

Cool on the baking sheets for 5 minutes, then carefully transfer to wire racks to cool completely.

Once cool, spread pumpkin butter on half of the cookies and top with the remaining cookies, pressing gently to seal.