Combine butter and brown sugar in bowl. Beat at medium speed, scraping bowl often, until creamy. Add chocolate; continue beating until well mixed. Add flour; beat at low speed until well mixed.
Knead dough with hands until dough sticks together.
Shape rounded teaspoonfuls of dough into 3-inch long bumpy “finger” shapes. (You will need to squeeze and pinch dough together to form fingers). Form rounded point for fingernail on one end.
Place 2 inches apart onto parchment lined cookie sheets. Make knuckle marks in dough using toothpick, if desired. Bake 10-12 minutes or until set. Remove from oven; immediately press 1 candy corn onto pointed end. Cool 5 minutes on cookie sheets. If the candy corn doesn't adhere to the cookie, simple add it right after glazing the cookies and they will stick.
Place cooling racks over waxed paper. Carefully move cookies from cookie sheets onto cooling racks. Cool completely.
Combine all glaze ingredients in bowl until well mixed. Lightly brush cooled cookies with glaze.