a small, square chocolate cake, often with nuts in it
Brownie
noun[ C ]uk/ˈbraʊ.ni/us/ˈbraʊ.ni/(UK also Brownie Guide)
女童子军（由7至10岁的女孩组成）
a girl aged between seven and ten (or between around seven and nine in the US) who is a member of the international organization for young women called the Guides, or the Girl Scouts in the US
UKThe girls wanted to join a Brownie pack(= group).女孩们想参加幼女童子军军团。
USThe girls wanted to join a Brownie troop(= group).女孩们想参加幼女童子军军团。