Sift first three ingredients together. Add egg yolks to buttermilk and combine with dry ingredients. Whip egg whites with cream of tartar and sugar until soft peaks form. Fold whipped egg whites into batter mixture.
In hot skillet add a little bit of butter or coat with vegetable spray. Place three or more slices down on hot skillet; top each carambola slice with approximately 2 tablespoons of batter. Cook until pancakes begin to form bubbles. Carefully turn cakes with spatula and cook until bottom side is golden brown.