If something is chocolatey, it tastes of chocolate or smells of chocolate. A chocolatey cake is full of that cocoa taste; a chocolatey kitchen is one where someone has been melting chocolate. The word is friendly and informal. Cooks, food writers, and ordinary people use it; a science paper would more likely say “flavoured with chocolate.” There is another spelling, chocolaty, which is the same word — American writing often drops the extra e. People also stretch it a little for colour: a chocolatey brown is that deep brown of a chocolate bar. The heart of the word, though, is the taste and the smell, not the colour.