Combine all ingredients for the pumpkin purée in a small saucepan over medium-low heat.
Mix until heated through then keep warm until ready to serve.
Preheat waffle maker.
Combine the gluten-free baking mix, flour, baking powder, baking soda, salt, and pumpkin pie spice in a large bowl. Mix well.
Whisk in the egg whites, oat milk, and honey. Mix until just combined.
Cook the waffles according to your waffle maker's instructions (usually about 6-8 minutes, until golden). Remove and keep warm.
While the waffles cook, whisk together the Greek yogurt, honey, and cinnamon. Set aside until ready to serve.
Top each waffle with a spoonful of the pumpkin purée and a spoonful of the yogurt mixture. Garnish with a sprinkle of powdered sugar and fresh berries.