Combine flour, sugar, baking powder, soda, salt in large mixing bowl.
Halve grapefruit, loosen sections with fruit knife.
Squeeze sections and juice into measuring cup and fill to one cup mark with orange juice.
In a separate bowl whisk together egg yolks, buttermilk, sour cream, melted butter, then adding fruit juice mixture.
Stir into dry ingredients to form moist batter.
Beat egg whites into stiff peaks and fold gently into batter.
Bake according to manufacturer's directions in preheated waffle iron until golden brown.
Dust with powdered sugar, sprinkle with blueberries & sliced almonds.
Serve immediately with warm LEMON CURD and hot SPICED ORANGE SYRUP.
See recipies for Lemon Curt and hot Spiced Orange Syrup