The 1801 census just says that there was a Christoffer Andersen who was 1 year old a Klunderud in Eiker. YOUR Christoffer Andersen was in 1819 said to be a potter in Drammen. The chuch record does not say where he was born. The confirmation record says Jacob lived at Lilleås. What it says about parents is normally a factual repeat of baptism record - also when a parent has died in the meantime or if the child was illegitimate. It does not mean that the parents were a couple in 1833, or living in Eiker.
(Klunderud is some distance away from Varlo and Lilleås)