To make the mango jam: In a medium sauce pan, heat the mangos, vinegar, and syrup until soft and all liquid is evaporated. Using a stick blender, blend until smooth. Let cool and set aside.
To make the lime crema: Combine all ingredients, mix, and keep cool. Set aside.
To make latkes: Using the grating attachment, grate the potatoes, onions, and yucca separately in a Cuisinart. Using a colander, squeeze all the excess liquid out of the grated vegetables.
Combine the potato, yucca, and onion mixture with eggs and flour in a mixing bowl, incorporating completely.
Add the oil to a medium skillet and heat to 370 degrees.
Place two ounces of the latke mixture to the oil and cook until brown on one side, approximately 2 minutes. Using a slotted spoon or spatula, flip the latke and continue to cook until browned on both sides. Remove from oil, place on a paper towel covered tray, and immediately season with salt. Continue with the remaining mix.
To serve: Top each latke with a dollop of jam and crema and serve immediately.