Martine and Myrna Bazin’s Sweet Potato Cake (Pain Patate)

Ingredients

• • 1 cup (210 g) brown sugar
  • 1 cup (150 g) unbleached all-purpose flour
  • 2 tsp baking powder
  • ¼ tsp salt
  • ¼ tsp ground ginger
  • ¼ tsp ground cinnamon
  • 3 white-fleshed sweet potatoes with purple skin (about 2.2 lb/1 kg), peeled and cubed (see note)
  • ¼ cup (55 g) unsalted butter, softened
  • ¼ cup (55 g) vegetable shortening, softened
  • ¼ cup (60 ml) evaporated milk
  • ¼ cup (60 ml) coconut milk
  • 1 tsp (5 ml) vanilla
  • 1 cup (140 g) raisins