Prepare the Sweet Potato Puree: Begin by preparing your 1 medium sweet potato. Peel and cube it. Boil, steam, or roast the sweet potato until it is very tender when pierced with a fork. Drain well if boiled, then mash thoroughly until smooth. Set aside to cool to room temperature. You will need about ¾ cup of sweet potato puree for the recipe.
1 medium sweet potato
Combine Dry Ingredients: In a medium bowl, whisk together the 2 cups all-purpose flour, 1 teaspoon baking powder, ½ teaspoon baking soda, ½ teaspoon ground cinnamon, ¼ teaspoon ground nutmeg, ¼ teaspoon ground ginger (if using), and ¼ teaspoon salt. Set aside.
2 cups all-purpose flour, 1 teaspoon baking powder, ½ teaspoon baking soda, ½ teaspoon ground cinnamon, ¼ teaspoon ground nutmeg, ¼ teaspoon ground ginger, ¼ teaspoon salt
Cream Butter and Sugars: In a large mixing bowl, using an electric mixer or whisk, cream together the ½ cup unsalted butter, softened, ½ cup granulated sugar, and ¼ cup packed light brown sugar until light and fluffy, about 2-3 minutes.
½ cup Unsalted butter, ½ cup granulated sugar, ¼ cup packed light brown sugar
Add Egg and Vanilla: Beat in the 1 large egg until fully incorporated, then stir in the 1 teaspoon vanilla extract.
1 large egg, 1 teaspoon vanilla extract
Incorporate Sweet Potato Puree: Add the cooled ¾ cup sweet potato puree to the wet ingredients and mix until well combined and smooth.
Combine Wet and Dry Ingredients: Gradually add the dry ingredient mixture to the wet ingredient mixture, mixing on low speed (or by hand) until just combined. Be careful not to overmix; a few streaks of flour are acceptable.
Chill the Dough (Optional but Recommended): Cover the bowl with plastic wrap and chill the cookie dough in the refrigerator for at least 30 minutes. This helps prevent the cookies from spreading too much.
Preheat Oven and Prepare Baking Sheets: While the dough is chilling, preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper or silicone baking mats.
Scoop and Bake: Drop rounded tablespoons of cookie dough onto the prepared baking sheets, leaving about 2 inches (5 cm) between each cookie.
Bake: Bake for 15-18 minutes, or until the edges are lightly golden and the centers are set.
Cool: Remove the cookies from the oven and let them cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.