Scoop small spoonfuls of the ice cream into the molds, packing it in to reduce holes and air bubbles. Freeze several hours until very firm. (How many you get will depend somewhat on the size of your silicone molds.
Place a cookie sheet or a large platter in the freezer to chill about one hour before dipping the bites.
In a heatproof bowl set over a pan of barely simmering water, melt the chocolate with the cocoa butter, stirring until smooth. Remove the bowl from over the pan and set on a kitchen towel (leaving it over the pan means it may stay warmer and your bites are more likely to melt).
Remove the cookie sheet or platter from the freezer and cover with waxed paper.
Working quickly, pop one bite out of the mold, leaving the rest in the freezer to stay cold. Dip quickly in the melted chocolate, using two forks to toss it and coat all over.
Lift out with one fork and tap the fork firmly on the edge of the bowl to remove the excess chocolate, then place the chocolate covered bite on the cold tray to harden.
Repeat with remaining ice cream bites. If at any time it seems like the covered bites are getting too soft, move them back into the freezer. You can keep another cookie sheet in the freezer for the finished bites.
To store the bites, simply wait until they are all nicely frozen and transfer to an airtight container.