Prep the cone: Place the cone on a piece of parchment paper, and use an offset spatula to cover it with the ruby chocolate. When the cone is completely covered, transfer it to the refrigerator to chill until firm, about 10 minutes. When the cone is set, pour the leftover chocolate into the center of your serving plate or cake stand and top with the cone. Transfer to the refrigerator to set, about 10 minutes.
When the cone is well-anchored to the serving plate, break a toothpick in half and insert the broken end into the bottom of the cone; allow 1/2-inch of the pointed end to stick out of the cone. (If this is hard to do, make a hole in the foam with the pointed end before inserting the broken end.) Place a truffle on the pointed end of the toothpick. Repeat this process until the entire bottom edge of the cone is covered with truffles. Begin a second row of truffles in the same way; position the truffles so that they rest on the bottom row. Repeat this process, traveling upward until the entire cone is covered.
Sprinkle the assembled centerpiece with gold star sprinkles, or leave plain. Wrap the cone in plastic wrap and store in the refrigerator until you’re ready to serve. If you have extra truffles that wouldn’t fit on the cone, place them in foil papers and serve around the centerpiece.
The ruby chocolate in this recipe can be evenly swapped for dark, semisweet, bittersweet, milk, or white chocolate.If you use another chocolate, the truffles can be rolled in unsweet cocoa powder or even ground nuts, such as pistachios, which would make a pretty green 'tree'.