What's the perfect age gap between babies?

Mrs.A
I'm 33 going on 34 this summer and we have an 11 year old and a 6 month old. We've always said we would have another baby but now hubby wants to try for a baby right after our youngest's first birthday, I'm unsure how crazy hectic it would be with a two year old and a newborn. I really wanted to wait until she would be in school to have another baby but having a baby at 37-38 kinda scares me too. What's the perfect age gap between babies?