Heat oven to 400 degrees F. Coat eight 6-ounce ramekins or custard cups with nonstick cooking spray. Add sugar to one ramekin, turn to coat bottom and side with sugar. Pour excess into next ramekin; repeat as above.
In a medium-size saucepan, combine pudding mix and milk. Over medium-high heat, cook, stirring, until mixture comes to a full boil. Remove from heat; stir in butter and chips. In medium-size bowl, beat eggs; stir in a little hot pudding mixture. Whisk egg mixture back into pan to blend.
Spoon about 1/2 cup mixture into each ramekin, dividing evenly. Place on baking sheet. Bake at 400 degrees F for 20 minutes.
Meanwhile, beat heavy cream with mint extract until soft peaks form. Let flan cool slightly; run thin metal spatula around edge. Shake gently; invert onto serving plate. Let stand 15 minutes, then serve. Spoon dollop of mint cream on side; garnish with a mint-chocolate candy slice and fresh mint, if desired. Makes 8 servings.