01 -
Preheat the oven to 350°F (177°C). Line two baking sheets with parchment paper.
02 -
Beat the softened butter, brown sugar, granulated sugar, and vanilla on medium speed for 3-4 minutes, until lighter and fluffy.
03 -
Mix in the sweet potato puree until smooth. Scrape down the bowl so no butter streaks remain.
04 -
Whisk the flour, baking powder, baking soda, salt, cinnamon, and nutmeg in a separate bowl.
05 -
Add the dry ingredients to the sweet potato mixture and mix on low just until combined. The dough will be soft and thick.
06 -
Scoop 2 tablespoon mounds onto the prepared baking sheets, leaving 2 inches between cookies. Bake for 10-12 minutes, until puffed and set around the edges.
07 -
Press one marshmallow half onto each cookie. Return to the oven for 2-3 minutes to soften, then toast with a kitchen torch or under the broiler for 30-60 seconds until golden.
08 -
Cool on the baking sheet for 10 minutes, then move to a rack. Sprinkle with cinnamon sugar if using.