Put everything but the shortening in the blender or food processor and spin until smooth. (Alternately, mix dry ingredients in a bowl and slowly mix milk in, until you get a runny batter.) Stick batter in fridge. Put 1T shortening into each of eight cups of a muffin tin. Set oven to 425F/220C and put muffin tin in. Let shortening melt for 10 minutes. Pour batter into melted shortening. Bake 20 minutes. (Yes, seriously, only let the batter rest for 10-15 minutes before you use it.)
Put the shortening in a microwavable 2c measuring cup. Nuke it for 1 min. Stir in the flour and cocoa powder, until smooth. Slowly stir in milk up to the 1c mark. (This may be lumpy. Don’t worry about it too much, yet.) Nuke that for 1m. Now add sugar and stir until smooth. Nuke that for ~30s and WATCH IT. If it starts to bubble up, it’s done. Stir it one more time and let it set while the cakes finish baking.
Take the cakes out and let them sit 2-3 minutes, before
lifting them out of the tray. They’ll come out easy, because of the
shortening, but DO NOT let them cool, or the shortening will glue them
to the bottom of the pan.