Sweet Potato and Molasses Cookies

Ingredients

• • 2 small sweet potatoes, about 1 lb (450 g)
  • 2 cups (300 g) unbleached all-purpose flour
  • 1 tsp baking soda
  • 1/2 tsp ground cinnamon
  • 1/2 tsp ground ginger
  • 1 pinch salt
  • 1/2 cup (115 g) unsalted butter, softened
  • 3/4 cup (180 ml) molasses
  • 1 egg