Step 1In a large mixing bowl, combine the ground masa, baking powder, cinnamon, sugar and piloncillo. Mix well. Add the corn oil and chicken broth, and continue mixing (the masa should be smooth). Add the candied pumpkin, but be careful not to overmix; you want to see chunks of the pumpkin in the masa.
Step 2Drain the corn husks and pat dry.
Step 3Scoop a 1/4- to 1/3-cup spoonful of masa mixture onto the corn husk and fold one side of the corn husk over mixture then fold the other side, overlapping, as if folding a letter. Fold the pointed side of the tamale up and turn over to keep it from coming undone.
Step 4Arrange the tamales upright in a tamale steamer (tamalera) filled to the line with water, and heat over medium-high heat. Cover the top of tamales with a layer of remaining husks and a damp towel.
Step 5Cover with lid and steam until the masa is set (test by pulling back the corn husk on a tamale; if the masa sticks to the husk, it still needs to steam), about 11/2 hours, adding additional water to the tamalera as needed.