Put the honey and cocoa powder on separate small plates. Prepare a glass by dipping half of the rim into the honey (take care to wipe off the excess), then the same half of the glass into the cocoa powder. Set aside.
Add the bourbon, vermouth, bitters and chile slice to a mixing glass and lightly muddle the chile to extract just a little heat. Add ice and stir the cocktail thoroughly. Using a julep strainer, slowly strain into the prepared glass, taking care not to aerate the liquid.