Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line it with parchment paper.
In a medium bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, and nutmeg.
In a large bowl, combine the granulated sugar, brown sugar, and vegetable oil. Mix in the eggs one at a time, then add the vanilla extract.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Do not overmix. Fold in the chopped rhubarb and nuts, if using.
Pour the batter into the prepared loaf pan and smooth the top.
Bake for 55-65 minutes, or until a toothpick inserted into the center comes out clean.
Allow the bread to cool in the pan for about 10 minutes, then transfer it to a wire rack to cool completely.