Add coca cola and sugar to a sauce pan or pot and heat on the stove top over medium high heat until gently boiling. Continue boiling until mixture has become thickened and syrupy (reduced to about ⅓ cup).
Stir in the sweetened condensed milk and bring back to a gentle boil. Remove from heat.
Pour hot mixture into a heat-safe bowl with the chocolate chips, butter, vanilla and 1 cup of the walnuts. Stir until chocolate is melted and everything is combined.
Spread the fudge mixture into a parchment lined 8x8 casserole dish and gently press remaining walnuts into the top of the fudge.
Chill in the refrigerator for at least two hours to set before slicing.
Notes
Calories are automatically generated. For best results calculate based on your exact ingredients.