Preheat oven to 325F (163C) and spray a loaf pan with non-stick cooking spray.
Mix pumpkin, yogurt, coconut sugar, and vanilla until combined.
1 cup pumpkin, ¼ cup nonfat Greek yogurt, ½ cup coconut sugar, 1 teaspoon vanilla extract
Add olive oil and egg. Mix well.
¼ cup light olive oil, 1 large egg
Add oat flour, whey protein, baking powder, baking soda, and cinnamon. Mix well.
1 cup oat flour, ¾ cup unflavored whey protein concentrate, 1 teaspoon baking soda, ½ teaspoon baking powder, 1 ½ teaspoons pumpkin spice
Pour into prepared loaf pan.
Bake for 35-40 minutes or until a toothpick inserted comes out clean.
Let cool in pan for 10 minutes, then remove from pan and let cool completely on a wire rack before slicing.