There is a general rule that if you eat a fruit or vegetable raw and it is not the local custom to eat it that way, you say "Shehakol".
Chocolate-covered espresso beans are mainly coffee beans with a thin layer of chocolate covering it. (I.e., the coffee is ikar). I am uncertain in the U.S. if it has become popular to eat raw coffee beans, but, I don't think so. Would the bracha still be shehakol b/c of the unpopularity of eating raw coffee beans, or should you say "ha'etz" as, even though it's covered in chocolate making it palatable, and the coffee is the ikar, this is now considered a "popular" way to eat coffee?