Preheat oven to 350° and spray a 9" X 5" loaf pan with nonstick cooking spray.
cooking spray
Grate the yellow squash.
In a large bowl whisk the flour, cinnamon, baking powder, baking soda and salt until combined; set aside.
1 3/4 cups flour, 1 tsp cinnamon, 1 tsp baking powder, 1/2 tsp baking soda, 1/2 tsp salt
Mix oil, sour cream, sugars, eggs, and vanilla together in a medium bowl. Stir in grated squash. Add squash mixture into the dry ingredients and mix until just combined. Do not over-mix.
1/2 cup canola oil, 1/4 cup sour cream, 1/2 cup sugar, 1/2 cup brown sugar, 2 eggs, 1 1/2 tsp vanilla, 1 1/2 cups grated squash
Pour batter into the prepared pan and bake about 1 hour, or until the top dries out and begins to crack, the loaf pulls away from the sides of the pan or a toothpick or cake tester comes out with only a few moist crumbs on it.
Let bread cool in the pan on a wire rack for about 30 minutes then take it out of the pan and cool completely.