I used to live near the Mount Lawley cafe strip in Perth and at that time I got addicted to visiting the Exomod cafe at 615 Beaufort Street, both because the drinks they make are fantastic (I became a big fan of their hot chocolates) and they always have decadent cakes to serve up too. Plus, it's one of the few places in Perth that actually opens late - apparently it's 24 hours over the weekend which is really rare.