These are a pair of Sapote.
The outer skin has a feel similar to a Kiwi, but without the fuzz. These fruit are best eaten when they are quite soft to the touch.
Open them up and inside is a single shiny black seed about the size of an almond or just a tad bigger.
I think this is one of the sweeter fruits so prefer just 1/2 a larger, or a small size fruit as a snack.
I serve them just cut, and with a spoon; the flavor is like a cooked spiced pear; you know, poach a pear with simple sugar, cloves, allspice, cinnamon, and voila, Zapote.
I'm not an ice cream eater, but I can see how they'd be a great addition to a bowl of plain vanilla ice cream. Or so I've been told.