Tres Leches Cake's Name Has A Very Literal Meaning
Tres leches cake is served up by many Mexican bakeries and restaurants here in the U.S. and is well known in Mexico, too, although other Latin American countries including Cuba, Puerto Rico, Nicaragua, and Venezuela also claim it as their invention. One thing no one seems to disagree about is the name since the Spanish phrase "tres leches" is an exact translation of "three milks" (or vice-versa, depending on who's doing the translating), and three different dairy products always feature in recipes for the cake.
As to what the three milks may be, there's a certain amount of wiggle room. Pastel de tres leches is often made from heavy cream, evaporated milk, and sweetened condensed milk and as two of these milks come in canned form, it's no surprise that the cake's renown may owe quite a bit to the Nestle company. Nestle not only made these ingredients widely available during the latter part of the 20th century, which seems to coincide with the cake's rise in popularity, but at one time it even published a cake recipe right on the cans for one or both types of milk. Mashed developer Molly Allen uses the aforementioned three-milk classic combo for her tres leches cake recipe, but several 21st-century spins on the dessert tweak it by using chocolate milk or flavoring the milk or cake batter with fruity cereal, pumpkin pie spice, or chai tea.
You can make a vegan version of tres leches cake
While such a dairy-heavy cake might seem to be an unlikely candidate for veganization, you can actually take the moo juice out of tres leches and still leave three "milks." The easiest ingredient to switch up may be the heavy cream since some recipes use whole milk in its place. Other recipes use whole milk instead of evaporated milk, so either or both can be replaced with almond, coconut, oat, soy, or any other plant-based milk you prefer. Sweetened, flavored plant milks will also work as long as you don't mind an extra-sweet dessert.
What can you use in place of the sweetened condensed milk, though? While sweetened condensed coconut milk may be available in some stores, you can make a DIY version pretty easily by combining three parts of coconut milk (the full-fat kind from a can) with one part sugar. You can also use the same canned coconut milk to make a substitute for the whipped cream frosting that typically tops a tres leches cake.