Cook the bacon in a 350F oven for 20 minutes or until crispy. I usually rinse and de-stem the tomatillos and add them to the same roasting pan as the bacon. Lining the pan with parchment paper makes for easy cleanup.
Once the bacon is cooked, reserve the bacon drippings. Strain the drippings into a jar or container. Add the roasted tomatillos to a blender or set them aside until you need them.
In a mixing bowl, combine 2 cups masa harina, 3/4 teaspoon salt, and 1 teaspoon baking powder. Add 2 tablespoons bacon fat and combine well.
Now add only 1 cup of the warm water and combine as much as you can using a spoon or spatula. I usually dump the mixture onto a work surface at this point and add the remaining water (approx. 1/2 cup) a few tablespoons at a time, kneading the dough until it comes together into a cohesive ball.
Rinse, de-stem, and finely chop a serrano pepper. Add it to the masa dough along with the finely chopped bacon. Combine well.
Pull off a 3 oz. chunk of masa dough and use your hands to roll it into a ball. (3 oz. is somewhere between a golfball and a racquetball.)
Surround the dough ball in plastic (I use a Ziploc bag with the top cut off) and use a flat-bottomed baking dish to flatten the dough ball to 1/4" thickness. Keep in mind that you can always make them thicker at the cost of a longer cooking time.
Pre-heat a dry skillet or comal to medium heat. Cook each side of the Gordita until light brown spots are forming, approximately 2-3 minutes per side.
Meanwhile, heat up a thin layer of oil in a separate skillet. I use a thermometer to get the oil up to 360F, and this corresponds to a medium setting on my stove.
Add the partially cooked Gordita from the dry skillet and cook it in the hot oil for 1-2 minutes or until the bottom side is brown and crispy. You can optionally cook the second side in the oil but I frequently will only cook the first side. Set aside to drain on some paper towels and continue cooking the rest of the Gorditas.
To finish the Salsa, add the roasted tomatillos to a blender along with 2 peeled garlic cloves and 2 chipotles in adobo. I usually de-stem and de-seed the chipotles. Combine well. If it doesn't combine readily you can add a splash of water to it.
Serve the Gorditas alongside the homemade Salsa.
Cooked Gorditas do not store well, but sometimes I will store leftover Gordita dough in the fridge where it will keep for a few days.