Cake can make a good poetry topic idea because it can be viewed both positively and negatively. As an example, consider birthday cake.
Birthday cake can been seen in a positive way. Birthday cake is very familiar. Its look and taste are generally recognizable. Birthday cakes are associated with happiness, parties and celebrations. They can be associated with surprises and presents. They can be associated with memories.
Birthday cake can also have a negative view as well though. Imagine someone eating a birthday cake alone because there was no one to spend their birthday with them. Imagine someone who has a sensitive feeling about their age, seeing their birthday cake. Think about someone making a cake and experiencing frustration during the process.
A poet, when using cake as a poetry topic, could pick one of these perspectives and the ideas within them, and use it as a focus of a poem. Additionally, a poet could mix the perspectives and use them together in one poem.
In addition to birthday cake, as well as the ideas about it described here, a poet could focus on other types of cake and situations related to cakes in a poem. Cake, generally, can be used as a device to explore more complex issues in a poem. If a poet wanted to focus on positive ideas such as familiarity, celebration, surprise or memories or negative ideas such as loneliness, sensitivity to something or frustration, cake can be used as a way to lead into or present the idea.
Please feel free to use the poetry topic idea described here as a focus for a poem.