peppermint essential oil(you can also use peppermint extract, you will need 1 teaspoon + 1/4 teaspoon, divided)
candies for topping
Line a 9x9-inch square baking pan with plastic wrap. I used two layers of plastic wrap - with each layer overlapping opposite ends. Press firmly all around the pan and be sure to cover all sides. Leave enough to overhang the pan and use the plastic as handles later to help remove the fudge.
Heat condensed milk, chocolate chips and butter over medium-low heat. To be safe, it is best to use a double boiler for this. Otherwise, use very low heat and watch very carefully, stirring constantly. Once the chocolate is melted, remove from heat and continue to stir until mixture smooth and creamy. If using peppermint essential oil, add 3 drops to the chocolate mixture and stir well to combine. If using peppermint extract use 1 teaspoon. Pour fudge into prepared pan, smoothing with the back of the spoon. Chill at least 30 minutes.
After the chocolate fudge base as chilled for a least 30 minutes. Melt white chocolate chips in a small glass, microwave-safe bowl. Use the "melt function" of your microwave or a medium power setting. Once the chocolate is completely melted, stir in 1-2 drops peppermint essential oil or 1/4 teaspoon peppermint extract. Pour white chocolate over the chocolate layer. Smooth with an offset spatula. Sprinkle with candies, pressing candies into gently into the white chocolate. Chill another 2 hours before cutting. Cut into small pieces.
I used peppermint essential oil in this recipe. I find it has a true and vibrant aroma and flavour. I prefer the essential oil to peppermint extract. However, peppermint extract is easier to find. Use 1 teaspoon of extract in the dark chocolate layer and a about 1/4-1/2 teaspoon in the white chocolate layer. I like fudge when it is cut in the teeny-tiny pieces, so I get 64 1x1 inch pieces. For toppings, I used these pretty little green candy gems. I think green sprinkles let us know this is mint fudge so their is no surprizes. Crushed up candy canes would be pretty too.