Bring a large pot of water to boil and add the potatoes. Boil them for 20-25 minutes, or until very soft.
Drain and add to a large mixing bowl with the butter, crema or sour cream, chili powder, cumin, and salt and pepper to taste. Mash until very smooth.
Heat the oil in a large pan or skillet over medium-high heat.
Warm the tortillas in the microwave or in a pan heated to medium-high – this will ensure they do not break.
Spoon ¼ cup mashed potatoes into each tortilla and fold them in half. Fry each stuffed tortilla in batches in the oil 2-3 minutes per side, or until crispy and golden. Drain on a wire rack or on paper towels. You can keep them warmed in the oven at 200 degrees F if needed.
Serve with your favorite toppings and salsa or sauce.
