Add the potatoes to a sauce pan. Cover with water, add 1/2 teaspoon of salt and bring to a boil. Reduce to a simmer and continue cooking until potatoes are fork tender. Remove from heat.
After a few minutes, drain the potatoes. Mash the potaoes, seasoning with just pepper to taste. Let them cool.
After potatoes have cooled, mix in the cracker meal and dried shrimp powder. The shrimp powder will add salt to the mix, so now you can taste it for salt. If you like more shrimp flavor, you could add more powder.
Pour a little oil in a bowl. Rub some on your hands and form your potato cakes. Place the cakes onto a plate lined with wax paper. Chill for at least 1 hour.
In a large skillet preheat enough oil at medium heat so it covers the bottom and comes up about 1/3 of an inch.
When ready, carefully transfer 4 of the potato cakes into hot oil. Do no overcrowd the pan. After 2-4 minutes, flip the potato cakes over. They are delicate and can break easily. Take your time to flip. Cook for another 2-4 minutes then transfer to a plate line with paper towels. Serve right away. Garnish with salsa or nopalitos!