Beat Neufchatel cheese with electric mixer until it's nice and fluffy. Beat in sour cream and confectioner's sugar. You can taste it at this point to see if it's sweet enough for you--no danger like with regular cheesecake batters with raw egg. If you think it needs more sugar, add by 1 tbs. I found it sweet enough for me with 1/3 cup of sugar.
I tinted my key lime filling with one drop of green food coloring. Key lime is actually yellow LOL...I did this just for eye appeal and it's totally unnecessary.
Now get 4 small dessert dishes and start layering the cheesecake with the key lime filling, alternating and ending with the cheesecake filling.
Chill well before serving, about 1-2 hours.
Makes 4 servings.