Lightly spoon flours into dry measuring cups, and level with a knife. Combine flours and the next 4 ingredients (flours through salt) in a large bowl. Combine buttermilk and egg whites; add to flour mixture, stirring until smooth.
Spoon about 1/4 cup batter per pancake onto a hot nonstick griddle or a large nonstick skillet coated with cooking spray. Turn the pancakes when tops are covered with bubbles and edges look cooked; cook for 1 to 2 minutes more or until golden.
Note: To freeze, cool the cooked pancakes completely on a wire rack. Place in a heavy-duty zip-top plastic bag, separating the pancakes with wax paper. To reheat, microwave pancakes at high for 45 seconds, or place in the toaster at medium-high heat for 2 cycles or until hot.