From POPSUGAR Food
Pour whiskey into a large mason jar or container with an airtight lid. Add cinnamon sticks and simple syrup. Stir gently. Cover, and let sit for 5 days in a cool, dark space.
After 5 days, open the cinnamon-infused whiskey, and add dried red chilies. Cover, and shake a few times to mix. Store for 2 more days.
After 7 days, strain whiskey through a cheesecloth or strainer to remove the cinnamon and chili peppers. Store in an airtight container for up to 3 to 6 months.