It mixes really easily. Mixture is too thick to use a blender though. I put my chocolate pack in a ramekin dish and add a tablespoon of water at a time (so as not to add too much = cow pat!) So add a tablespoon of boiling water, mix it in, then another tablesoon, mix that, then another tablespoon. You shouldn't need too much more than that. Just enough to make sure there no powder left. It's just very thick and sticky, level it off (no need to beat or whip as with cake mixture - just stir it in) and pop in the microwave for approx 1 minute, maybe 1min 20secs (Depending on microwave)
Granted its not your usual "Chocolate Muffin" but it puffs up (though sinks a little when you take it out a bit like a souffle) gives you something to chew and tastes a damn sight better than ANOTHER shake.
Good luck!