A hearty, sweet-and-spicy beef and bean chili with balanced heat from cayenne and red pepper flakes, mellowed by a touch of brown sugar and finished with a splash of apple cider vinegar.
Heat olive oil in a large pot over medium-high heat until shimmering.
Add onion and bell pepper; cook, stirring, until softened and lightly golden, about 5 to 7 minutes.
Stir in garlic and tomato paste; cook until fragrant and slightly darkened, about 1 to 2 minutes.
Add ground beef; cook, breaking it up, until browned and no longer pink, about 6 to 8 minutes. Drain excess fat if needed.
Sprinkle in chili powder, cumin, smoked paprika, cayenne, red pepper flakes, salt, and black pepper; cook 1 minute to toast spices.
Pour in beef broth and scrape the bottom of the pot to release browned bits. Add crushed tomatoes and tomato sauce; stir to combine.
Stir in kidney beans, black beans, brown sugar, and cocoa powder. Bring to a gentle boil, then reduce heat to low.
Simmer uncovered or partially covered, stirring occasionally, until thickened and flavors meld, about 40 to 45 minutes.
Stir in apple cider vinegar. Taste and adjust seasoning: add more salt for savoriness, a pinch of sugar for sweetness, or cayenne for extra heat. If too thick, thin with a splash of broth.
Serve hot with your favorite toppings like shredded cheddar, sour cream, green onions, or tortilla chips.
Notes
Chili tastes even better the next day. Store up to 4 days in the refrigerator or freeze up to 3 months. For milder heat, reduce cayenne and red pepper flakes; for sweeter chili, add 1.0 additional tbsp brown sugar.