To prepare batter, lightly spoon flour into a dry measuring cup; level with a knife.
Combine flour, baking powder, flax seeds, 1 tablespoon coconut sugar, salt, and 1/8 teaspoon cinnamon in a medium bowl, stirring with a whisk.
Combine egg whites, coconut milk, coconut oil, and vanilla in a small bowl, stirring with a whisk.
Let stand 30 minutes.
Preheat oven to 425 degrees
To prepare apple mixture, coat bottom and sides of a 10 inch ovenproof skillet with cooking spray.
Combine 1/4 cup Z sweet, cinnamon; sprinkle half of mixture evenly over bottom and sides of pan. Arrange apple in an even spoke-like layer in pan.
Sprinkle apple with remaining sugar mixture.
Cook over medium heat 8 minutes or until mixture bubbles.
Slowly pour batter over apple mixture.
Bake at 425 for 15 minutes.
Reduce oven temperature to 375 (do not remove pancake from oven); bake an additional 13 minutes or until center is set.
Carefully loosen pancake with a spatula. Gently slide pancake onto a serving platter.
Sift powdered sugar over top. Cut into 6 wedges; serve immediately.