Look like mangoes is that likely?

Definitely not. They're smaller than mango.

they look like paw paws to me.
is the inside of the fruit sorta custard like ?

Paw paw was what jumped into my head too.

Hi dirt_farmer and Cararose: I don't think so. look at the pic. The fruit taste sweet and bitter.

They may be Avocados. There is a seedless variety of them also.
If you puree them in a blender do they look like Avocado dip?

Is it Sapote?

No. Sapote is only in Asia where hot weather allows and it's dark brown color when ripe.

The leaves look just like the ones on my giant Avacado tree, but my fruits have huge seeds.

Casimiroa?

WHITE SABOTE - CASIMIROA :) THAT'S IT.... THANK YOU NONMEMBER. THIS CASE IS CLOSED.

Native to Central Mexico, sapote (Casimiroa) was named for Spanish botanist Casimiro Gomez de Ortega (1741- 1818), who directed the formation of the Royal Botanic Garden of Madrid and was the first professor there. This was the garden where Spanish explorers sent the wealth of plants discovered on their travels in the New World. The genus Casimiroa comprises a half-dozen species, the majority of which remained local. The most popular and well-traveled species, C. edulis, was so called because the flesh of the fruit was delightfully edible. Known as white sapote or, simply, sapote, it was planted in countries enjoying a mediterranean climate, but did less well in tropical climates. The common name in Spanish is zapote blanco, derived from the Nahuatl word tzapotl, used to describe many soft and sweet fruits. Zapote became sapota in Latin and sapote in English. Ironically, the family Sapotaceae is full of plants bearing soft, sweet fruits, but Casimiroa is not a member. Rather, it is classified in the citrus family (Rutaceae).

Franciscan missionaries introduced sapote to California in 1810; there was at least one planted at Mission Santa Barbara around 1820. The fruit was well thought of in Los Angeles by the 1850s, and nurseries, such as CA Reed’s Tropical Nursery in Santa Barbara, were offering it for sale soon after.

Many tropical and subtropical fruits have soft flesh, but sapote fruit is exceptionally soft, which makes harvesting, storing, and shipping a challenge, if not an outright barrier, to commercial production. So sapote has been relegated to specialty growers and enthusiasts of its rich fruit. The flesh is the consistency of custard, with a skin that is easily punctured; if bruised, the flesh turns bitter, ruining the fruit. The best flavor develops when the fruit is tree ripened; the stem naturally releases the fruit when ripe, whence it falls from the tree, often with a splat. If the fruit is twisted off from the stem, a bruise develops at the separation point. The best harvest technique is to clip the stem from the tree when the fruit is almost ripe. The fruit can then be stored on a counter or in a refrigerator until the stem falls off, at which point it is fully ripe. The volume of fruit produced generally exceeds the greediest of appetites. If harvesting is delayed, the ground beneath the tree will soon be decorated with splattered fruit.

Fruit carefully harvested is eaten with a spoon and makes a rich desert; it can also be included in fruit salads or pureed and added to ice cream or blended drinks. The native people also used sapote trees medicinally; seeds and leaves were used as a sleep aid, although their effectiveness is contested by medical practitioners today. The more Casimiroa is studied, the more possibilities emerge: today researchers are looking at its isolated alkaloids and flavonoids for their ability to inhibit mutating cells, in the hope of combating cancer.
- See more at: http://www.pacifichorticulture.org/articles/orchard-trees-of-rancho-los-cerritos-sapotes/#sthash.ICxiqgaK.dpuf

Casimiroa is not named for Gomez Ortega but for a different Casimiro Gomez, an indigenous Mexican (Otomi) hero of Mexico's war of independence.

Here is a link that might be useful: Novorum Vegetabilium Descriptiones 1824