Cut the tops and bottoms off of the corn cobs, then shuck the cobs carefully and save the husks for later. Cut the kernels off the cobs and mix them together in a blender until you have a smooth paste.
In a separate bowl, fluff up the vegetable shortening before adding the sugar. Then, blend in the salt, baking powder, and your choice of add-ins. Transfer the corn paste to the bowl and mix everything together. Remember, the batter should be thick, but creamy.
Add a few scoops of corn mixture to the wide end of a corn husk. Keeping it horizontal, fold one side of the husk over the center, then tuck the other side on top to form a tube shape. Where the dough ends, pinch the bottom and fold the husk upwards. If the husks are small, secure the tamal by wrapping another husk around it the opposite way. Continue this process until the rest of the batter is gone.
Add some water to the bottom of a large stockpot. Place a steamer rack inside and cover it with a layer of the leftover corn husks. Lean the tamales around the steamer in an upright position. Continue working inwards in a circular fashion until the pot is full. Cover the tamales with another layer of corn husks and a tea towel on top. Put the lid on your pot, bring to a boil, then reduce the heat and steam the tamales until they’re fully cooked. Happy eating!