Preheat a waffle iron according to the manufacturer's instructions.
Into a small bowl, stir together the water and flaxseed meal. Set aside for 10 minutes, until slightly thickened.
Into a large mixing bowl, stir together the all-purpose flour, granulated sugar, cornstarch, baking powder, cinnamon, salt, ginger, nutmeg, and pumpkin pie spice.
Add the unsweetened almond milk, pumpkin puree, butter, and flaxseed mixture. Beat on medium speed until well combined.
Onto the prepared waffle iron, pour 1/2 cup batter. Sprinkle with 2 tablespoons pecan pieces.
Bake until golden and crisp, according to manufacturer's directions, about 3 minutes.
Repeat with remaining batter and pecans.
Serve hot with maple syrup.