This Question neatly describes the best way to mine for incredibly rare ores. This is all well and good.
I don't want the rare stuff though, as crazy as that sounds. I want stacks upon stacks upon STACKS of cobblestone to build myself a sprawling elaborate stone fortress.
I am aware that Cobblestone Generators exist, but I feel my one-block-at-a-time generator is incredibly inefficient, and especially so when, half of the time, my cobblestone falls into the lava and I have to wait for a new one to appear.
I also feel like it's distinctly possible that "just digging' may be my best bet, but I keep running into massive blocks of dirt and gravel that annoy me to no end.
So, what is the quickest, easiest, and most efficient way to mine a ton of cobblestone?