Add 4 teaspoons of water to the mix. If this seems too thick, add only enough to make it a smoother mix. Watery batter is not a plus. Let this little cake bake for 13-15 minutes. The heat source is a light bulb.
Timing varies according to how much batter the child actually gets into the pan.
Filling much over half full isn't recommended. Set a timer. Read a little story book or two. Safety is the paramount issue. The child needs oven mitts, supervision, etc., at all times.