Preheat the oven to 350 degrees Fahrenheit. Bring 6 cups of water to a boil and keep hot.
Beat the lard with a hand mixer or the paddle attachment of an electric mixer until fluffy (60-90 seconds). Add in in the masa harina, chili powder, cumin, baking powder, and salt. Beat until all ingredients are well incorporated and there are no lumps. Slowly add in the chicken broth or water a little at a time until the mixture resembles the consistency of cake icing. Beat for another 6 minutes, then set aside for 15 minutes to let the ingredients moisten and rise.
Combine the BBQ sauce with the shredded chicken and corn in a large bowl. Toss to coat.
Scoop the tamale dough out into a 13" x 9" baking dish and smooth with a spatula (or your hands).
Spread the chicken and corn mixture evenly over the top of the sauce. Add black beans on top, followed by all of the shredded cheese.
Cover the dish with foil, using toothpicks to keep the foil from touching the cheese and sticking. Place the casserole dish on top of a rimmed baking sheet or other large oven-proof dish with tall sides (such as a roasting pan), and place in the oven. Once in the oven, pour the very hot water into the rimmed baking sheet so the tamale pie bakes in a bath of about two inches of water.
Bake for 45 minutes, then remove the foil and bake for another 10-15 minutes, or until the tamale base is set and cooked through.
Meanwhile, place the sliced red onion and sliced jalapeno in separate bowls. Cover with vinegar and let sit 1 hour to pickle.
When tamale pie is done, remove from oven and let cool 15 minutes. Top with chopped cilantro, scallions, pickled red onion and jalapeno. Serve with extra BBQ sauce.
Before you ask, YES you need to use lard. Just trust me.