Serves: About 8 waffles
Preheat a waffle iron to medium-high. Preheat the oven to 95°C (to keep cooked waffles warm). Whisk together the rice flour, chickpea flour, tapioca flour, sugar, baking powder, vanilla and salt in a large bowl. Whisk together the milk, oil and egg yolks in another bowl. Beat the egg whites in a third bowl until soft peaks form, about 3 minutes.
Pour the milk mixture into the rice flour mixture and gently stir until just incorporated (it's ok if there are some lumps). Fold in the egg whites.
Lightly brush the top and bottom of the waffle iron with oil. Fill the waffle iron about three-quarters of the way full (some waffle iron should still be showing). Close the lid gently and cook until the waffles are golden brown and crisp, 6 to 7 minutes. Keep the cooked waffles warm in the oven or covered with foil on a plate while you make the remaining waffles.
Serve with butter and maple syrup.