Step 1

Preheat the oven to 350 degrees F.

Step 2

Line two baking sheets with parchment paper.

Step 3

In the bowl of a stand mixer fitted with the paddle attachment, add the butter, the brown sugar, the granulated sugar, and the vanilla extract, creaming the mixture together until it is light and fluffy, about 5 minutes.

Step 4

Add the sweet potato purée to the butter mixture and beat to combine.

Step 5

Use a silicone spatula to scrape the bowl well, then beat the sweet potato mixture, about 1 minute.

Step 6

In a medium bowl, add the flour, the baking powder, the baking soda, and the salt and whisk to combine.

Step 7

Add the flour mixture to the sweet potato mixture and mix on low speed until the dough is evenly combined, about 1 minute.

Step 8

Scoop the dough into 1/4-cup mounds and stagger them 2 inches apart on the prepared baking sheets.

Step 9

Place the baking sheets in the oven and bake the cookies until they are lightly golden around the edges, about 10-12 minutes.

Step 10

Transfer the baking sheets from the oven and gently press 1 of the marshmallows on top of each of the cookies.

Step 11

Bake the cookies until the marshmallows have melted over the surfaces and are slightly toasted, about 7-9 minutes.

Step 12

Transfer the baking sheets to wire racks and let the cookies cool, about 5 minutes.

Step 13

Place the cookies on the wire racks to cool completely, about 15 minutes.

Step 14

Serve.