Heat a large cast-iron pan over medium heat, add 2 tablespoons of the olive oil and heat through. Add the corn and cook until slightly charred, stirring occasionally, about 3 to 5 minutes. Remove and set aside. Reserve 1 cup of the kernels for serving.
Add the rest of the corn to a food processor with 1 egg and queso fresco, pulsing until creamy. Season to taste with salt and pepper. Cover and refrigerate until ready to use. The filling can be made ahead of time and frozen until ready to use for up to 1 month.
Cut the dough into 4 equal pieces and cover with plastic wrap. Dust a clean surface with semolina flour (or cornmeal) and working one piece at a time, flatten the dough into a 5-inch by 4-inch oval. Roll the dough through a pasta machine at the widest setting. Fold the dough in thirds (like a letter) and run it through the machine again. Continue to roll the dough through the machine, reducing the setting to narrower settings each time until it is 1/16-inch thick. You should be able to see your hand through the dough.
Cut the sheet in half crosswise. Starting one inch from the short edge, spoon 1 tablespoon of the corn filling down the length of the dough spacing them about 1” apart. In a small bowl whisk together the remaining egg with 1 tablespoon of water.
Brush the filling with the egg wash and cover with the second piece of the dough, pressing around each round so no extra air remains. Use a sharp knife to cut the ravioli into 2” inch squares. Cover with plastic wrap until ready to use. Repeat with the remaining dough and filling.
Bring a large pot of water to a boil, add the ravioli and cook until the ravioli rises to the top and are al dente, about 3 minutes. Drain then toss with the remaining olive oil and set aside.