base it on 5 paragraphs
1st paragraph = introduction (introduce subject)
body paragraph 1 = introduce 1 thing or idea
body paragraph 2 = introduce 2nd thing or idea
body paragraph 3 = introduce 3rd thing or idea
5th paragraph = conclusion (conclude/summarize all these ideas)
You can talk about the history of candy bars, when the first one was made and who/when/where. you can talk about the different types, and maybe how some are vegan/gluten free/more nutritional, etc.