Soak the corn husks in a bowl of very hot or boiling water for at least 30 minutes.
In a large bowl, use an electric mixer to beat the lard and 1 tablespoon of broth until fluffy, about 3-5 minutes.
Combine the masa harina, baking powder, salt, cumin; stir into the lard mixture and beat well with an electric mixer.
Add more broth as necessary to form a very soft dough. Beat on high speed for several minutes.
To test if the masa tamale dough is ready, place a tiny ball of dough into a glass of water— If the dough floats, it’s ready. If the dough sinks to the bottom of the glass then beat it for longer and add a little more broth. Test again. It should spread like creamy peanut butter and be slightly sticky.
Lay a corn husk, glossy side up, on the counter with the wide end at the top. Scoop a big rounded tablespoon of masa (or more if you want bigger tamales) and place it towards the top-half of the corn husk.
Lay a piece of plastic wrap over the dough and use your hands to press and spread the masa into a thin layer, about 1/4 inch thick, along the top half of the corn husk.
Spoon a tablespoon of filling in a line down the center of the dough.
Fold in one long side of the husk about 1/3 over dough and filling. Fold in the other long side, overlapping the first (like folding a business letter). Fold the bottom of the husk up.
Add water to the bottom of your steamer or instant pot. (about 1 cup water, or enough to cover the bottom of the pot and not go above the wire rack.
Place tamales on rack in steamer or instant pot, standing upright, with the folded end down and open end up. Don’t over-pack the pan, just pack them tightly enough to keep the tamales in an upright position.
Steam for 50 minutes - 1 hour in the steamer, or, if using an Instant Pot, cook on Manual for 18-20 minutes, depending on how big you made the tamales. Allow pressure to naturally release for 10 minutes, and then quick release.
To test if they’re done, remove one and try to pull the husk off. If it comes off easily and cleanly, they're done.