Preheat oven to 400°F and line a baking sheet with aluminum foil.
Wash potatoes, poke holes with a fork, coat with olive oil, and season with salt and pepper.
Bake potatoes for about 45 minutes until tender.
In a skillet over medium heat, cook ground beef and diced onion until browned; drain excess fat.
Add taco seasoning and water to beef mixture, simmer until thickened.
Melt Velveeta, pepper jack cheeses, and evaporated milk over low heat, stirring until smooth to make cheese sauce.
Broil baked potatoes on low for 15 minutes for a crispy skin.
Cut open each potato, fluff inside with a fork, fill with cheese sauce and taco beef mixture.
Top with desired garnishes such as grated cheese, tomatoes, jalapenos, sour cream, and cilantro.