Aspects of the design that are entirely your original work, such as a piped or carved design, may be protected by copyright as a work of visual art; the US Copyright Office has asserted that permanence is not required for protection.
The author of a creative design is the owner of the copyright automatically.
Copyright someone elses design
If the design meets the minimum requirements for copyright protection, yes.
A novelty cake is a cake that is new (novel) and it is a design that you wish to have
If you control the copyright, anywhere. If you don't control the copyright, and don't have a license, nowhere.
Yes, if the web design legally belongs to you. Add © copyright YEAR NAME OF COPYRIGHT HOLDER to the bottom of each page of the website. This will signal to honest people that the web design is copyrighted and may not be used elsewhere.
They can help you design your own cake.
Architectural works are protected by copyright.
The controversy surrounding the Trump inaugural cake was about its design and origins. Some people claimed that the cake was a replica of one made for Obama's inauguration, while others argued that it was an original design. The baker of the cake, Duff Goldman, confirmed that the cake was indeed a replica of Obama's cake.
Design cakes.
Ideas cannot be protected by copyright, only the expression of the ideas.
Copyright protected or trademark images, such as cartoon characters, require licenses from their owners.