In a mixing bowl, dissolve the lemon Jell-O in boiling water.
Stir until thoroughly mixed.
Add cold water and stir ingredients to combine.
Place bowl in refrigerator and refrigerate approximately 15 minutes.
Add cheesecake pudding mix and lemon extract and whisk into Jell-O mixture until pudding mix is completely dissolved.
Refrigerate mixture an additional 20 minutes.
Add softened cream cheese, whipped topping, undrained crushed pineapple, 1 ½ cups marshmallows and all but two tablespoons of the nuts.
If desired, transfer mixture to a glass serving bowl, trifle dish or parfait dishes.
Refrigerate mixture for 2 hours.
Garnish fluff with remaining marshmallows, diced nuts, maraschino cherries and a lemon slice curl (if desired.)
Refrigerate until ready to serve, or overnight.