I did - last night.
I dreamt that I had uncovered a thin, 7/7 liquid vein of Hot Fudge. Fortunately I did this by channeling into it from above, so I didn't spill it.
Immediately after that, I tapped into a cavern underneath this. It was entirely filled with white squares. I checked what they were: Vanilla Ice Cream.
Heck yes, I thought! Vanilla ice cream cavern! And the hot fudge is right over it! What luck! I immediately set my dwarves to tap into the vein and have it drain into the ice cream cavern to see what would happen. I figured it had to be good.
As soon as the hot fudge hit the ice cream, I got a whole bunch of job cancellations:
Urist McMiner cancels Dig: Ice cream sundaes!!
Pages and pages of "Ice cream sundaes!!" job cancellations filled my announcement window as every single conscious dwarf in the fortress dropped what they were doing and RAN at incredible speed to my ice cream cavern. I've never seen dwarves book it so quickly. Other than a few injured or sleeping dwarves, every single dwarf in the place ran down there all at once. Some started paddling around in the ice cream in big loop-de-loops, others hung out around the side of Lake Sundae.
I was worried as to what would happen to them down there, but it seemed like every dwarf who was partaking of "Ice cream sundaes!!" had the happiness level of "beyond ecstatic", and they didn't get hungry or thirsty down there. Finally, the frolic was over and they started up with their normal jobs again, but they all had the thought "... has combed ice cream residue out of his/her beard lately" in their thoughts list. And they were all very, very happy.
Then I woke up.