For the sauce: Heat the oil in a medium skillet over medium heat. Add the garlic and cook until fragrant, about 2 minutes. Add the chili powder, cocoa powder, cinnamon and cumin and saute until toasted and fragrant, about 2 more minutes. Add the tomato paste and cook 1 minute, then add the tomato sauce and chicken broth and whisk until smooth and combined. Stir in the peanut butter, brown sugar and a pinch of salt. Bring to a simmer and cook for 10 minutes to thicken. Remove from the heat.
For the enchiladas: Wrap the tortillas in a damp paper towel and microwave in 30-second internals, just until warmed through and pliable. Add the chicken to a medium bowl and pour about 1/2 cup of the mole sauce over top; toss to coat the chicken. Spread another 1/2 cup of the mole sauce in the bottom of an 11-by-7-inch baking dish.
Place one warmed tortilla flat on a clean work surface. Top with 1/4 cup of the chicken filling and 2 tablespoons of the shredded cheese. Roll up and place seam side down in the prepared baking dish. Repeat with the remaining tortillas, filling and shredded cheese. Pour the remaining mole over the top of the rolled tortillas. Cover the dish with foil and bake until the cheese is melted and the mole is bubbling, 25 to 30 minutes.
Remove from the oven and top with the crema, queso fresco and sesame seeds. Serve garnished with cilantro leaves.
This recipe can also be doubled and baked in a 9-by-13-inch baking dish.