I am doing a wedding and Groom's cake at a venue that requires vendor's insurance. I have purchased, in the past, a vendor's insurance policy for a 24 hour period. I am not seeing anywhere that offers an annual policy instead of a day policy. This is my 3rd venue that has required it so looking without success for the annual policy. 

You might try State Farm. I have an annual policy through them that I find very reasonable and it covers so much-- even things like your computer software in case your laptop is stolen. I'm still a very small business, but its comforting to know I'm covered.