Heat the oven to 350 degrees F and arrange four small 5-inch individual cast iron skillets on a baking sheet (you may need two baking sheets depending on the size of your skillets).
In a large non-stick skillet, sauté the pancetta (or bacon) until the fat is rendered. Be careful not to let it burn. Drain the cooked pancetta on a plate lined with paper towels, reserving enough pork fat in the pan to keep it greased (about 1 teaspoon).
In the same skillet over medium high heat, sauté the summer squash in the pork fat until just tender (about 5 minutes). Transfer the squash to a bowl and set aside.
Lower the heat to medium and add the diced green pepper. Sauté until softened (about 5 minutes). Sprinkle with the dried spices – cumin, red pepper flakes, paprika, salt, and pepper – and stir in the tomato paste to coat. Cook for another 5 minutes until fragrant, stirring frequently.
Add the diced tomatoes to the pan bring to a simmer. Let the sauce reduce for about 15 minutes until thickened.
As the sauce cooks, grease the individual cast iron skillets with non-stick spray. Line the bottom of the pan with the squash, layering the slices so that they overlap. Divide the pancetta among the skillets, sprinkling it over the squash.
When the sauce is thickened and seasoned to your liking, divide it among all four skillets (each should hold 1 to 1 ½ cups of sauce). Use a spoon to make a little indentation in the center of each, making the skillets like little nests.
Crack one of the eggs into a small ramekin or prep bowl, being careful not to break the yoke. Carefully pour the whole egg into one of the skillets, so that the egg yolk settles into the nest you made. Don’t worry if the egg white spreads out across the surface – it will cook just fine. Repeat this process with each egg and each skillet.
Sprinkle the top of each skillet with the fresh basil. Bake for 15 minutes, and then check to see if the egg is cooked to your liking. The whites should be set, but the yellow still over easy. I like my eggs on the gooey side, but if you prefer them a little more cooked, bake for another 5 minutes as needed.
Remove the baking trays from the oven and sprinkle them with the cotija cheese. Remember that they will be extremely hot. To serve, layer a kitchen towel or paper towels on serving plates large enough to accommodate the skillets. Place the individual egg bakes on each plate and serve.