Use a small-ish bowl, about 6 ounces. If you have custard ramekins (didn't everyone get a set of these as a wedding present??), one of those would be prefect.
Right in the bowl, add:2T flour
2T sugar (I mix white and brown)
2T cocoa powder (unsweetened baking cocoa)
pinch baking powder (optional, but improves texture)
2t (teaspoons) olive oil
Mix it right in the bowl.
Add liquid last after the dry ingredients are mixed.
It will make a thick batter. Don't worry if it's a smidge lumpy.
Sprinkle with chopped nuts, chocolate chips or other favorite goodies (also optional)
Microwave for a minute.
Serve immediately with a spoon.
Whipped cream or ice cream are optional.
Lots to like about this process. You probably have all the ingredients on hand right now. There is no waste, unless someone doesn't finish theirs. You can customize with the sprinkles. It's dairy-free for those who can't have dairy. It is pretty inexpensive. It's really fast.
A few notes to the baker:
I wipe the bowl rim with a clean damp cloth after mixing and before microwaving. Looks better when you serve it...
Microwaving will cause the ingredients to approximately double in volume.
If you are making multiples for a larger crowd, mix the dry, line up the bowls and have 2 fully mixed, then add liquid about a minute in advance of putting each additional one in the microwave. Probably best not to have them sitting around wet. I don't recommend more than 1 in the micro at a time, but if you experiment let us know the results!
I'm at 5,000 feet altitude and 30% humidity. If yours is too gooey it could be that you have more humidity which increases the moisture of the dry ingredients. In that case, back off on the water a bit.