Start by piercing a whole sweet potato with a fork, then microwave it for about 5–7 minutes until tender. Alternatively, roast at 400°F for 45–60 minutes. Mash until smooth, yielding about ½ cup.

In a large mixing bowl, cream together softened unsalted butter, brown sugar, and granulated sugar using an electric mixer for about 2 minutes until fluffy. Add the egg, vanilla extract, and mashed sweet potato, mixing well.

In a separate bowl, whisk together all-purpose flour, cinnamon, nutmeg, ginger, baking soda, and salt until evenly mixed.

Gradually add the dry mixture to the wet ingredients, stirring gently until just combined. The dough should be thick and slightly sticky.

Preheat the oven to 350°F and line a baking sheet with parchment paper. Use a tablespoon to drop rounded balls of dough onto the sheet, leaving space in between. Optionally, press a pecan onto each dough ball.

Bake for 10–12 minutes until edges are golden and centers are soft. Remove and cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.