Soak cornhusks in hot water until soft (about 30 minutes to 1 hour). While corn husks are soaking, Combine chicken, enchilada sauce, pureed salsa, green chilies, salt, cumin, onion powder and garlic in a large bowl and set aside.
Using a large mixing bowl and electric mixer on medium speed, blend masa harina, canola oil, baking powder and the 4 cups chicken broth. Beat the masa until it feels like mash potatoes. Season the masa to taste with salt and pepper to taste. Set masa mixture aside
Tamale Assembly: Place 3 Tablespoons masa mixture on the smooth side of the softened cornhusk and spread into a 4x4-inch square (on the square base of husk). Place two tablespoons of the seasoned shredded chicken down the center of each masa. Roll the cornhusk lengthwise from right to left. Fold the tamale tail end under and place on tray with folded end on bottom. When 2 dozen tamales are completed, cover and place in refrigerator. When all tamales are made, you can either place them into gallon Zipper bags to freeze or you can steam them.
Steaming Tamales: Use a vegetable steamer pot or electric steamer. Fill steamer pot with the amount of water recommended by manufacturer. Loosely arrange the tamales, open end up, in steamer basket and arrange so that the steamer basket is full (don’t crowd as tamales will expand). Cover tamales with leftover shucks to retain steam. Bring water in steamer pot to a boil, cover and reduce heat to medium low. Cook tamales for 60 minutes or until masa pulls away from shuck and is cooked.