Preheat oven to 400 degrees. Lightly grease or spray a 9x13-inch baking dish, set aside.
In a large skillet set over medium-low heat, add the chicken, broth, sauce, cilantro, and garlic powder. Heat while preparing the remaining ingredients, stirring occasionally.
In the bowl of a food processor, combine the masa, salt, sugar, baking powder, pepper, butter, 2 cups corn, and poblanos. Process or pulse until a coarse meal forms. Add chicken broth and process or pulse until them mixture reaches a thick peanut butter consistency. More broth (or water) may be required. Fold in remaining 1 cup of corn.
Press half of the mixture into the bottom of the prepared pan. Sprinkle with 3/4 cup cheese, then add the chicken filling. Sprinkle with another 3/4 cup cheese. Press the remaining tamale dough over top.
Cover with 1 cup of chile verde sauce and remaining 1 1/2 cups cheese. Place a piece of foil over top and place in the oven to bake for 30 minutes. Uncover and cook for an additional 10 minutes. Top with cilantro, if desired.