Belfast-based firm Ashers Baking Company was found guilty of discrimination last month, following the incident.
The firm said it would not make the Sesame Street cake which celebrated gay marriage because it conflicted with the owner’s religious beliefs.
Describing it as a “deliciously difficult subject," he replied: “Finally I found myself on the side of the bakers.
“It was not because it was a gay couple that they objected, it was not because they were celebrating some sort of marriage or an agreement between them.
“It was the actual words on the cake they objected to. Because they found the words offensive.
“I would support their rights to say no, this is personally offensive to my beliefs, I will not do it.”
Professor Graham Walker, a politics academic at Queen's University Belfast, said the case had proven a "phyrric victory" for the gay rights movement in Northern Ireland.
He told HuffPost UK: "The verdict has created a difficult context for movement on this issue. It has made opponents of gay marriage here all the more defiant and determined.
"There was considerable sympathy for Ashers across the sectarian divide and indeed beyond. There were even letters in The Guardian regretting the outcome. It is hard not to conclude that this case should never have gone to court."