The Beracha recited over a chocolate bar that contains nuts is "She’ha’kol." The chocolate is clearly the primary component, while the nuts are secondary, and therefore one should recite "She’ha’kol" over the chocolate, and this Beracha covers the nuts.
If one eats nuts with a thin glaze of honey, the Beracha is "Ha’etz." Although Hacham Bension Abba Shaul (Israel, 1924-1998) was uncertain about which Beracha to recite, the consensus among the Poskim is that the thin glaze is subordinate to the nut, and therefore the Beracha of "Ha’etz" covers the glaze.
However, if one eats peanuts that are coated with dough, then the Beracha is "Mezonot." There is a fundamental rule that if a food product contains flour, then even if the flour constitutes a small minority of the food, nevertheless, it is considered the primary ingredient and the Beracha is "Mezonot," unless the flour is added only to keep the ingredients together. As long as the flour is added for purposes of satiation, and not just for the consistency, it is considered the primary ingredient. Therefore, the Beracha over peanuts with a coating of dough is "Mezonot."
Summary: The Beracha over a chocolate bar with nuts is "She’ha’kol." The Beracha over nuts that have a thin honey glaze is "Ha’etz." The Beracha over a nut covered with dough is "Mezonot."
