When in KL, consider a day or overnight trip (preferably on the weekend) to Melaka/Malacca, another UNESCO world heritage city and much closer vs Penang. Good Nyonya/Peranakan (i.e Baba Ang) eating among other things. Stay @ Liu Men or Majestic hotel.
Some other related recs
In Singapore, explore the HDB (Housing Dev. Board) hawker centers. Where the non-hipster OG locals dine.