I don't normally think of candy when I think of potatoes but here are two recipes which show it can be done. The origin of the candy is unclear to me but I immediately think it must be Irish. I've read that some people it is German or possibly even Canadian but I haven't yet seen a definitive answer.

Regardless of who thought this one up, it seems like it would taste good. I imagine the potato lending a soft starchy texture which is bland enough not to compete with any added flavorings and other ingredients.

Potato Candy
1 medium cooked potato, hot
a little butter
flavor
1 lb. confectioners sugar
coconut
nuts, chopped finely
chocolate, melted

Mash the potato and add in a little butter. Add flavoring. Work in 1 lb. of confectioners sugar. Add coconut and nuts. Press into a greased pan and spread chocolate on top. Since there aren't any proportions, you'll just have to go by guess on what looks right. The next recipe has measurements and is quite similar.

Potato Coconut Candy
1 medium-sized potato
2 cups sifted confectioner's sugar
1 tablespoon corn syrup
2 cups shredded coconut
1 teaspoon vanilla
melted chocolate

Boil and mash potato. It should make about one-quarter cup. Add sugar, corn syrup, coconut and vanilla. Mix or knead until well-blended and smooth. Press into one-inch thick layer in a buttered pan. Spread top with thin coating of melted chocolate or cut into squares and dip in chocolate or roll in chopped nuts.

I'm sure the flavorings could be adjusted as well, a bit of maple flavoring or even rum might be fun in these candies. I'm placing it on my list of things to try and will post a photo once I do.