Preheat oven to 350°F. Grease 9- x 5-inch (23 x 13 cm) loaf pan and line with parchment paper.
In large bowl, whisk together flour, baking powder, baking soda, salt and cinnamon. In separate bowl, whisk together eggs, pancake syrup, yogurt, coconut oil and vanilla until blended; whisk in bananas.
Stir egg mixture into flour mixture; fold in walnuts, if desired. Scrape into prepared pan; smooth top. Bake for about 50 minutes or until tester inserted into center comes out clean. Let cool completely in pan on rack.