Infusions
Fill a large basin with water and place an immersion circulator inside. Set the circulator to 145°F. Put the cocoa butter and vodka in a bowl and stir to combine. Transfer to a sealable, heatproof plastic bag. Seal the bag almost completely, then remove as much air as possible by dipping the bag (other than the unsealed portion) in the water. The counterpressure from the water will push the rest of the air out. Finish sealing the bag, then remove it from the water. When the water has reached 145°F, place the bag in the basin and cook for 2 hours. Transfer the bag to an ice bath and let cool to room temperature. Pass the infusion through a fine-mesh sieve lined with several layers of cheesecloth. If any particles remain in the infusion, strain it again through a paper coffee filter or Superbag. Transfer to a container, cover, and freeze for 24 hours. Strain again through a fine-mesh sieve lined with several layers of cheesecloth, then funnel back into the bourbon bottle and refrigerate until ready to use, up to 3 months.