- Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper. 
- In a large bowl, whisk together the mashed sweet potato, sugar, melted coconut oil, egg, and vanilla extract until smooth. 
- In a separate bowl, sift together the flour, baking powder, baking soda, salt, and ground cinnamon. 
- Gradually add the dry ingredients to the wet ingredients, mixing until just combined. The dough will be slightly sticky. 
- In a small bowl, combine the granulated sugar and a teaspoon of cinnamon for rolling. 
- Using a tablespoon, scoop dough and roll into balls, then roll each ball in the cinnamon-sugar mixture until coated. 
- Place the dough balls onto the prepared baking sheet about 2 inches apart, and gently flatten each slightly with your palm. 
- Bake for 10-12 minutes, or until the edges are set but the centers remain soft. 
- Remove from oven and allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.