Step 1

Arrange a rack in the middle of the oven and heat the oven to 425°F. Prick 1 large sweet potato all over with a fork. Wrap in aluminum foil and place on a baking sheet lined with aluminum foil. Bake until tender, 45 to 50 minutes. (Alternatively, microwave on HIGH until tender, about 10 minutes.) Let cool, then scoop out the flesh into a large bowl and mash with a fork; keep 1 cup in the bowl reserve any extra for another use.

Step 2

Reduce the oven temperature to 350°F. Move the middle rack into the lower third. Line an 8x4-inch loaf pan with parchment paper and coat with cooking spray.

Step 3

Add 1 teaspoon kosher salt, 3/4 teaspoon ground cinnamon, 1/4 teaspoon ground nutmeg, 1/4 teaspoon ground cardamom, 1/4 teaspoon ground allspice, and 1/4 teaspoon ground ginger to the sweet potato and whisk until combined. Add 1 cup canola oil, 1 cup granulated sugar, and 1/3 cup packed brown sugar, and whisk until combined.

Step 4

Whisk in 3 large eggs, one at a time. Sprinkle 1 1/2 teaspoons baking powder and 1/2 teaspoon baking soda over the surface of the batter and whisk vigorously until combined. Add 1 3/4 cups all-purpose flour and stir until just combined. Transfer into the pan and smooth the top. Sprinkle with 1 tablespoon turbinado sugar.

Step 5

Bake for 40 minutes. Rotate the pan and bake until a tester inserted in the center comes out clean, 30 to 35 minutes more. Place the pan on a wire rack and let the bread cool completely in the pan before removing and slicing.