You are doing the right things keep them up.

Some additional ideas:
-sell chocolates online (Mail order)
-Monthly promotions - special flavor of the month on ice cream, half price on certain items during off-peak times
-Various Holiday promotions - Thanksgiving, Christmas, St. Patricks, etc.
-Contests - partner with radio and newspaper - crate a new flavor/dessert, etc. best recipe wins something worthwhile.
-Institute a can food drive during the holidays again partner with radio and newspaper
-Promote your chocolate workshops to senior centers, after school programs, area clubs, etc.
-Promote party space for adult events (currently you only do childrens parties).
-Partner with local eateries to sell your chocolates or swap offers of discount coupons to each others customers.
-Create news - identify a trend and send out a press release on it to local media. Do a survey and announce results in a release. Position yourself as an expert in chocolate/desserts, etc.

Think of different ways to engage all the demographics in your town. Different things appeal to different age groups as well as to men and women.

Stick with it.