Preheat the oven to 350 F and line a 9 x 5 inch pan with parchment paper.

Rub the brown sugar and zests together. Mix in the oil. Add the eggs one at a time and mix well. Add the orange juice and vanilla.

In a separate bowl, mix the dry ingredients together. Add the dry ingredients to the wet, mix to just incorporate. Pour into the pan.

Bake 40 - 45 minutes, until a toothpick inserted in the center comes out clean. Let cool in the pan for 15 minutes and then remove from the pan and cool completely.