Prick 1 sweet potato with a fork and microwave until tender, 8 to 10 minutes. Peel, mash and let cool. Mix 1 1/2 cups flour, 1 tablespoon baking powder, 2 teaspoons jerk seasoning and 1 teaspoon kosher salt in a bowl. Cut in 1 cubed stick butter. Stir in 1/4 cup half-and-half and the sweet potato. Knead, then pat into a 5 1/2-inch round. Cut into 8 wedges. Bake at 425 degrees F until golden, 15 to 20 minutes.