MASH bananas thoroughly. Measure exactly 3 cups prepared fruit into 6- or 8-quart saucepot.
Add lemon juice and fruit protector; stir until well blended.
STIR in pectin.
Add butter to reduce foaming, if desired.
Bring mixture to full rolling boil (a boil that doesn't stop bubbling when stirred) on high heat, stirring constantly.
ADD sugars; stir until well blended. Add walnuts and spices; mix well. Return to full rolling boil and boil exactly 1 minute, stirring constantly.
Remove from heat.
Skim off any foam with metal spoon.
LADLE immediately into prepared jars, filling to within 1/8 inch of tops. Wipe jar rims and threads. Cover with 2-piece lids. Screw bands tightly.
Process 10 minutes in a hot water bath or use the inversion method. Remove jars and place upright on towel to cool completely. After jars cool, check seals by pressing middle of lid with finger. (If lid springs back, lid is not sealed and refrigeration is necessary.).