[cake is the Best reward, obviously. Hotaru's look of remorse at not having an answer is far more important to Adrien than the lack of answers themselves (he can figure all that shit out Later, preferably while wearing a magical cat suit after finding his partner, because it is Definitely Not Marinette) and so he's quick to try to reassure her:]

It's okay, even only knowing that much helps a lot. It's good to know I should be grateful my arrival was just being covered in glitter and confetti. Awkward, sure, but not dangerous. I'm glad you got out of that alright.