Preheat the oven to 350° F(175°C). Spray a mini muffin tin with nonstick cooking spray.
Heat a large skillet over medium heat. Add the oil. Once hot, saute the onion and garlic for 2-4 minutes. Add the shredded meat and enchilada sauce. Stir to combine. Lower the heat and simmer until all the liquid in rendered out, about 10 minutes.
Meanwhile, mix the masa, baking powder, salt, and cumin together in a bowl. Add the water and mix to a crumbly consistency.
Lay out a piece of plastic wrap. Form the masa into a block, about 1/2” high on the plastic wrap. Cut it into 16 squares. Set the squares on the baking sheet.
Bake for 20 minutes, or until firm and starting to brown.
Cool for 5-10 minutes, then top with the enchilada mixture.
Garnish with crumbled cotija and cilantro. Serve warm.