Put the chocolate in a medium bowl. Bring the heavy cream to a simmer in a small saucepan over medium-high heat. Pour the hot cream over the chocolate and shake the bowl to gently settle the cream. Add the vanilla and a pinch of salt. Let sit until the chocolate melts, about 1 minute. Whisk the mixture until smooth and shiny. Cover with plastic wrap. Place the ganache in the fridge to set up for 30 minutes
Line a baking sheet with parchment paper. Scoop balls of chocolate, about 1-inch high or about 1 tablespoon, onto the parchment. Use your hands to roll each into a smooth ball.
Pour the jimmies into a small bowl and roll the truffles one at a time until completely coated. Place back onto the parchment and refrigerate until ready to use.
Meanwhile, make the Santa hats. Line a baking sheet with parchment. Place the red candy melts into a medium microwave-safe bowl with 1 tablespoon of the oil. Microwave in 1-minute intervals, stirring between each, until melted and smooth, about 2 minutes. Transfer the candy to a pastry bag or small zip-top bag and snip a small hole in the corner. Place the toothpicks about 2 inches apart on the prepared baking sheet. Pipe the red candy melts over each toothpick in the shape of a Santa hat, keeping the toothpick in the center with some exposed on the bottom (like a lollipop).
Add the white candy melts to a medium microwave-safe bowl with the remaining 1 tablespoon oil. Microwave in 1-minute intervals, stirring between each, until melted and smooth, about 2 minutes. Transfer to a pastry bag or small zip-top bag and snip a small hole in the corner. Pipe a white ball at the top of the hat and white fur along the bottom rim of the hat (making sure to keep enough toothpick exposed at the bottom to stick in the truffle). Refrigerate the Santa hats until set, about 10 minutes.
Stick one hat in each truffle and refrigerate until ready to serve if not serving immediately.