Preheat oven to 350 degrees F. Line a loaf pan with parchment paper or great it. Whisk together flour, pumpkin pie spice, salt, baking powder and baking soda in small bowl. Cream together sugar, yogurt and egg whites in a large bowl. Mix in pumpkin pie spice then slowly mix in dry ingredients. Pour into loaf pan. Mix together cinnamon and sugar then sprinkle evenly over the top of bread mixture. Bake in oven for 90 minutes. Half way through, press down sugar crust, if needed. To check for readiness, insert a butter knife into the center; if it comes out clean it's done, otherwise bake a little longer. Allow to cool before transferring to wire rack. Mix together powdered sugar and water to make icing then drizzle over the top.