Heat a Belgian waffle iron according to the manufacturer’s instructions. In a large bowl, whisk together the flour, sugar, chia seeds, poppy seeds, flax seeds, baking powder, and salt. In a separate medium bowl, whisk together the buttermilk, melted butter, orange zest, vanilla and egg. Add the wet mixture to the dry mixture and stir until just combined.
Scoop ¼ of the mixture into the waffle iron and spread it towards the edges. Cook the waffle until golden brown and crisp. Repeat with remaining batter. Serve the waffles immediately with butter and maple syrup.