I need a little help.....how do I make the minnie mouse ears for my cake

I would make them out of gumpaste or either 50/50 : 50% gumpaste and 50% fondant. I've made them out of Rice Krispy Treats before and covered them with black fondant but I personally prefer making them out of gumpaste. If you use only fondant they may "droop" or fall off because most fondant doesn't completely harden. Good luck!

Or dark chocolate piped/poured onto parchment and left to set.

I make mine with fondant.Cut the ears with a round cutter the size you need.Leave it a few days to dry and then I glue a wooden skewer on the back..let it dry and poke it down into the half ball for the head...

I mad mine with black candy melts - though it would work with dark chocolate as well. I filled circle cutters laid on parchment or wax paper with the chocolate. So I ended up with discs of chocolate - I also made the hat out of chocolate; I used a half ball pan and just did a layer of the chocolate on the inside of it. To attach the ears, I just used some more of the chocolate in a piping bag. To make them fit onto the hat, I took a larger circle cutter and cut a bit off of the edge of the ears when they had hardened just enough to hold their shape, so they almost looked like fat crescents. It gave me more surface area to attach to the hat. I liked this because I had heard that ears made out of fondant could be very heavy and hard to attach well to the cake.

If I ever do it again, I'll take more time to keep everything cleaner with neater edges - my edges were definitely a bit rough - but I was in a rush and it was my own (2 year old) daughter's cake, so it didn't have to be perfectly perfect!