Receptacles in Kitchen Cabinets
You do not need to move your electrical boxes out.
Just use these plastic extension fillers.

You might want to remove the receptacles as they can get stuck behind the cabinets if the &quot;ears&quot; on the receptacles are not removed.
Ears are the thin pieces of removable metal tabs on the top and bottom of the receptacle.  They have cut lines on them and can be removed using a pair of needle nose pliers.