Line a cookie sheet with parchment paper. Set aside.
Put the chocolate and butter in a large bowl. Set aside.
Using a small sauce pan, heat heavy whipping cream until slightly boiling
Pour the hot whipping cream over chocolate mixture in bowl and let stand 2 minutes. Using a whisk stir mixture until smooth.
Using a 9x9 baking pan, pour the mixture into the pan
Refrigerate at least one hour (but three hours is ideal), or until firm enough to shape.
Pour the halloween sprinkles into a large bowl. Using a small ice cream scooper, scoop out some of the truffle mixture and then roll into a ball.
Roll the truffle into the sprinkles and place ball onto a prepared cookie sheet. Repeat steps until all truffle mixture is used.
Put each truffle in a container with tight-fitting lid and refrigerate for at least 1 hour. (or until firm)
Store in your refrigerator.
Notes
PRO-TIP: I find using a cookie scoop is much better than using a kitchen spoon to scoop the filling and roll into balls. It creates the perfect size truffle!