STRAWBERRY SAUCE: Combine frozen strawberries, maple syrup and 2 tablespoons water in a large saucepan. Bring the mixture to a boil. Then reduce the heat to medium-low and simmer for 10 to 15 minutes, or until the sauce reaches a syrupy consistency and coats the back of a spoon. As the sauce simmers, break up the whole berries with a wooden spoon or fork.
While the sauce is simmering, prepare pancake batter: In a large mixing bowl, whisk together the flours, cocoa, sugar, flax seed, baking powder and salt.
In a medium bowl, lightly beat the whole egg and egg white. Then add the milk, oil and vanilla extract and whisk until combined.
Pour the wet ingredients over the dry ingredients and stir until the batter is just blended and no dry streaks remain. Take care not to overmix, as this will cause the pancakes to be chewy. Delicately fold in the chocolate chips. If time allows, let batter rest for 10 minutes.
When strawberry sauce has reached syrupy consistency, remove from heat.
Liberally coat a large skillet or griddle with oil spray. Preheat it over medium heat. After two minutes, ladle about 1/4 cup batter per pancake onto the surface.
Cook the pancakes until small bubbles from around edges, 1 to 2 minutes. Flip the pancakes over and cook about 1 minute longer. Recoat the skillet with oil spray between batches to prevent the pancakes from sticking.
To serve, top 2 pancakes with about 1/3 cup warm strawberry sauce and a sprinkling of chocolate chips on each plate.