For the buttermilk waffles, mix flour, baking powder, sugar and salt.
Mix the liquid ingredients well as well, mix the dry and liquid ingredients of the waffle batter until smooth and let rest for 10 minutes.
Preheat the waffle iron and grease it. Spread about 125 ml of the batter on the waffle iron, close the lid and bake the waffle for about 2 minutes until golden brown. Do the same with the rest of the batter.
Serve the buttermilk waffles garnished with mint.