Step #1 In a large microwave-safe bowl place both semi-sweet chocolate chips, milk chocolate chips, condensed milk & butter; microwave on MEDIUM for 3-5 mins, removing & stirring once or twice during the cooking time (do not overcook or the mixture will turn grainy).
Step #2 At this point mix in the 1 c mini marshmallows (if using) until completely mixd.
Step #3 Stir in vanilla & nuts until mixd.
Step #4 Transfer into greased 8 x 8-inch baking dish.
Step #5 Chill in refrigerator.
Enjoy the Easy Chocolate-Shop Microwave Chocolate Fudge recipe