Heat brown sugar, butter, corn syrup, cocoa powder, cinnamon, and cloves in a saucepan over medium-high heat until butter is melted, stirring constantly. Bring cocoa mixture to a rolling boil; boil for 1 minute.
Remove cocoa mixture from heat; stir in vanilla extract. Fold puffed wheat cereal into cocoa mixture. Pour cereal mixture into prepared pan; press evenly into the pan. Allow to cool completely before cutting into squares, about 30 minutes.