A great tres leches—a sponge cake soaked with a mixture of “three milks" (heavy cream, evaporated milk, and sweetened condensed milk)—should be moist but not mushy. It should be sweet but not sickeningly so. For our ideal Tres Leches Cake recipe, we needed to make our cake sturdy enough to handle the milk mixture, so we used whipped whole eggs instead of the egg whites that most recipes use. Although some tres leches recipes use equal amounts of evaporated milk, sweetened condensed milk, and cream, we found that cutting back on the cream produced a thicker mixture that didn’t oversaturate the cake.