Grease 8" x 8" square baking pan.
Combine sugar, lime zest, Persian Lime Olive Oil, lime juice, butter and sour cream in a 2-quart saucepan over medium heat for 5 minutes or until sugar is dissolved and mixture boils, stirring constantly.
Continue boiling over medium heat until candy thermometer reaches 238°F. Remove from heat, stir in marshmallows and white chocolate until melted and mixture is smooth.
Immediately pour fudge into greased pan and let stand 10 minutes until top is firm to touch. Using a knife, score top of fudge. Refrigerate about 1 hour until cool and firm. Cut out fudge.