In a large bowl, stir together the whole wheat flour, oats, cornmeal, flaxseed meal, brown sugar, baking powder, and baking soda. Pour in buttermilk and egg. Stir just until smooth.
Heat a large skillet or griddle over medium heat. Coat with cooking spray. Drop batter by large spoonfuls onto the griddle, and cook until bubbles form and the edges are dry. Flip, and cook until browned on the other side. Repeat with remaining batter.