How to make chocolate flavored "cheese"

Yesterday morning, as part of my attempt to limit caffeine leading up to a weekend full of races, I decided to have warm milk.  Often, I just sweeten it a bit with agave nectar and go.  Sometimes I splurge and make hot chocolate.  Yesterday, I split the difference and went for a warm hot chocolatey-protein drink.  Warm milk plus a couple scoops of the Luna Recovery Protein Smoothie (Chocolate!) that I like so much mixed with cold milk.  Like most powdered protein mixes, the Luna stuff is recalcitrant about going into solution and often leaves chunks of sugar/mix floating on the surface. 

So I thought nothing of it on my drive to work, during which I struggled to get a few drips of my concoction out of my travel mug.  A bit of extra swirling did the trick, clearly (in my head anyway) chunks of mix were just blocking access to the morning's treat.  Little did I know...  after getting to work, I whipped out a spoon to mix vigorously again.  Only to discover that what was in my mug resembled something more like a thick, brown cottage cheese than hot chocolate.  Something in the Luna drink plus warm milk catalyzes some kind of curdling reaction.  Trust me, I will not try that again.