Heat oven to 350°F. Grease either a 8x4 or 9X5 inch loaf pan.
Grab a large bowl. Stir the oil, eggs, mashed sweet potato, sugars and vanilla together.
Sift the flour, baking powder, salt, cinnamon and nutmeg over the wet mixture.
Fold the ingredients together until they are well combined but do not over-mix. It is ok if the batter is a little lumpy.
Bake in the pre-heated oven for 50 to 60 minutes if you use a 9x5 inch pan or an extra 10 minutes if you use a 8x4 inch pan. Check the bread with a toothpick. When a toothpick inserted in the middle comes out with just a few crumbs on it, it is done.
Cool in the pan for 15 minutes then remove the bread from the pan and let it cool on a wire rack.
Notes
You will need a little less than one pound of sweet potatoes, usually 1 large or 2 small potatoes.
You can use canned sweet potatoes if you can find them.
For fresh sweet potatoes, there are a few ways to cook them:
If you cook them in the oven, heat the oven to 400°F. Stab the potatoes with a fork a few times then stick them on a baking tray.
If you cook them in the microwave, stab them with a fork a few times and cook them in the microwave for 6 to 10 minutes or until they are soft.
After the sweet potatoes are cooked, the skin slides off very easily.
If you want to cook them on the stovetop, peel them first then slice them into quarters. Toss them in a pot of boiling water for 5 to 8 minutes then drain them and pat them dry with paper towels.