Chili powder and cumin are in most chili recipes. Other optional spices include: cayenne, smoked paprika, chipotle powder, aleppo pepper, or red pepper flakes. It really depends on the amount of spice you want. Chipotle powder, cayenne, and red pepper flakes will all give you a spicier chili. Start with less, and add more to taste. It’s easier to add spice than it is to take it away.