Chocolate is, apparently, very dangerous to dogs. I am amazed this clevel doggie got the wrappers off the cupcakes. they're tricky to peel off even for humans.
My brother had a dog that would steal chcolate. So one eatser, he hid the Easter eggs in a cupboard, tied rope on the door, which was tied to the banister in a way that you couldn't open the door unless you cut the rope. He then put a load of things in front of the door so there was no way the dog could get in. He then went out the house, happy in the knowledge his dog couldn't poison itself and he would still have his Easter eggs this year!
However, the string was broken by the dog, and the items moved by the dog out of the way. All his Easter eggs were eaten, the only thing remaining was the boxes and wrappers.
My brother had two dogs at the time, one much bigger than the Easter egg munching one. The big one would often open the kitchen door, then the small one would open the fridge with her paw. Then the bigone wouuld get items off the sehelve the little one couldn't reach. then the entire contents of the fridge would be shared between the two dogs, leaving only the crap stuff. If it was nice, they ate it. If it wasn't, they left it for us! Yet they got fed plenty. A lock on the fridge still didn't stop them, and eventually they broke the entire fridge door off its hinges!