Legal analysis: When the patent administration department of the State Council deems it necessary, it may require the design patent applicant to submit product samples or models using the design. The volume of the sample or model shall not exceed 30 cm × 30 cm × 30 cm, and the weight shall not exceed 15 kg. Perishable, fragile or dangerous goods shall not be submitted as samples or models.
It can be seen from this that the cake itself cannot apply for a design patent.
However, if you want to use a registered pattern as a cake pattern, such as a cartoon image, etc., it will involve patent ownership issues. If you want to use it, you can make appropriate processing improvements to make it different from the original image.
Legal basis: "Patent Law of the People's Republic of China" Article 22 Inventions and utility models for which patent rights are granted shall possess novelty, creativity and practicality.