Pour in the milk, egg, melted butter (or oil), and vanilla. If you’re adding mashed banana or cinnamon, now’s the time. Stir until just combined — lumps are totally okay.
¾ cup milk (dairy or unsweetened almond/oat milk), 1 egg, 2 tbsp melted butter or oil (plus more for the pan), 1 tsp vanilla extract, Optional: ½ mashed banana or ½ tsp cinnamon for a twist!