For the best texture, use avocados that are just ripe and not overly soft so the fat bombs hold their shape well. If you prefer a smoother result, beat the softened cream cheese with a hand mixer before adding the avocado. To minimize browning, press plastic wrap directly onto the surface of the fat bombs before sealing the container, and keep them well chilled. You can freeze the fat bombs on a parchment lined tray until solid, then transfer them to a freezer-safe container for longer storage and thaw in the refrigerator before serving.