In a cast iron skillet (or regular if you don't have cast iron), cook the bacon until crispy.
Once cooked, remove from skillet, crumble, and set aside.
Add the onion to the skillet and allow to saute in the bacon grease until golden brown and soft.
Sprinkle in the chili powder and cayenne pepper. Stir.
Pour in the beans and chicken stock.
Using a potato masher or large fork, mash beans to desired texture.
Stir a few times and keep over medium heat until heated through.
Stir in the cilantro, bacon, and desired amount of salt/pepper.
Serve!! *Garnish with additonal cilantro and shredded cheese if desired.