WHOLE, EVAPORATED, CONDENSED.
Whew, now that's out of the way - I read somewhere that tres leches cake (which means three milks' cake) was invented by canned milk companies in a ploy to increase their sales. Isn't that interesting? The recipe has really stuck around.
For good reason. The just perfectly viscous mixture of milks. The way the cake has a gradation of custardiness - the top retaining more of the original sponge texture, and the bottom also with a sponge texture, just that of one absolutely saturated with sweet milk. The lightly sweetened cushion of whipped cream on top.
I could go on and on. When you're deluged with work, emails, and just general stress, I highly recommend stopping whatever you're doing, remembering that chronic stress leads to cancer (I will have written & defended at least 35 pages on the matter by mid-April), and making this cake!