I'm not sure about the sales but you can get a rough idea of the interest in these by looking at google.com/insights/search/#q=frozen%20chocolate%20bananas&geo=US Also, if you have the sales figures for any other comparable item, you could do a quick comparison in google.com/insights/search/#q=frozen%20chocolate%20bananas%2Cfrozen%20bananas&geo=US&cmpt=q' Google Insights like this

Go with googlekeywordsadword tool ( adwords.google.com/o/Targeting/Explorer?__u=1000000000&__c=1000000000&ideaRequestType=KEYWORD_IDEAS#search.none ) in that select the country United States and then search with kewords like frozen chocolate bananas, chocolate bananas etc and what you will find lot of similar keywords with global and local searches, so you will get the idea what people search and that will be useful to your business.