Prepare the masa dough by mixing masa harina, warm water, and salt in a bowl until a smooth dough forms. Let it rest for 10 minutes.

In a skillet, heat vegetable oil over medium heat. Add onion and garlic, sauté until translucent. Add nopalitos, cumin, and chili powder, cooking for 5 minutes.

Divide the masa dough into 8 equal portions. Flatten each portion into a disc, place a spoonful of mashed beans and nopalitos mixture in the center, then fold and seal to form an oval shape.

Cook the tlacoyos on a preheated comal or skillet over medium heat for 4-5 minutes per side until golden brown.

Serve hot, topped with crumbled queso fresco and chopped cilantro.