What "cartoon" episode of Sabrina the Teenage Witch is this?

I'm looking for this cartoon episode of sabrina the teenage witch where things are explored about sabrina having a half moon on her hand, meaning half witch, i think. To get a full moon on her hand she has to like sacrifice something and she has to go to this forbidden tree in the middle of a spooky town. there is another scene that i remember where she is in cl making something in her cauldron and she puts something wrong in it like silver or something and it bubbles everywhere. I WOULD LOVE TO WATCH IT AGAIN!!! :D