Sorry if this sounds a bit basic but what do we know about how indigenous peoples prepared and consumed peanuts? Did they boil them, dry them, bake them, grind them up, press them for oil, or...what?
The most common preparation method appears to have been roasting them in their shells. They were also roasted shelled. These methods were common throughout the areas where peanuts were grown. They were also eaten raw, either freshly harvested or dried, but roasted peanuts appear to have been preferred.
In the eastern foothills of the Andes, where the peanut was probably domesticated, the range of preparation methods is diverse. Peanuts, ranging from immature to fully ripe, freshly harvested to dried, are eater raw, roasted in the their shells, roasted shelled, toasted, boiled, etc. Today, they are also fried in oil, but this is probably post-Columbian. They are used in cooked dishes, either ground to a paste in soups, stews, and sauces, or (less often, I think) as whole nuts, and rarely in soups as whole pods (harvested immature).
It was also used to make beverages, with some described as "peanut milk" and probably similar to European almond milk, and others probably similar to modern Bolivian and other peanut drinks such as chicha de mani.
Post-Columbian, they were used as subsitutes for almonds and other nuts in European style cooking, especially in desserts and sweets. The only possibly pre-Columbian use in sweets I know of is a dish of peanuts and honey, eaten by the Peruvian elite.
Pressing them for oil is post-Columbian.
Further reading:
Stalker, H. Thomas Wilson, Richard F., (2016), Peanuts - Genetics, Processing, and Utilization, AOCS Press has an excellent chapter on the early history of the peanut, with a table listing the 17th century and earlier written sources.
J. Smartt (ed), The Groundnut Crop: A scientific basis for improvement, Springer, 1994 also has a good chapter on the early history of the peanut, though without the detailed overview of the earlier literature in Stalker.
Andrew F. Smith, Peanuts: The Illustrious History of the Goober Pea, University of Illinois Press, 2002 obviously covers the history of the peanut, but has less on the early history, and is largely devoted to the US (including the colonies that became the USA) history of the peanut. But it has recipes.