Preheat your waffle iron and lightly grease it with oil or nonstick spray.
In a large mixing bowl, whisk together the eggs, Greek yogurt, milk, melted coconut oil, and vanilla until smooth.
Add almond flour, coconut sugar, baking powder, baking soda, salt, pumpkin pie spice, and optional cinnamon on top of the wet mixture.
Gently mix until just combined. The batter will be thick; however, if too thick, add a splash more milk.
Scoop batter into the preheated waffle iron, but don’t overfill it.
Cook until golden brown and crisp, about 4–5 minutes depending on your waffle maker.
For the optional Greek yogurt “icing,” mix ½ cup Greek yogurt with 1 tablespoon honey, ⅛ teaspoon vanilla extract, and optional pumpkin spice.
Serve waffles warm, with a dollop of the yogurt icing on top, and optionally with berries, maple syrup, or nut butter.