Prepare the Fudge Base

1. Melt Chocolate: In a medium saucepan over low heat, combine semi-sweet chocolate chips and 1/2 cup of sweetened condensed milk. Stir until melted and smooth.
2. Add Vanilla: Remove from heat and stir in the vanilla extract. Pour the mixture into a greased 9×9-inch baking dish, spreading it evenly.

Make the Second Layer

1. Melt White Chocolate: In the same saucepan, combine white chocolate chips and the remaining sweetened condensed milk. Stir over low heat until melted and smooth.
2. Add Food Coloring: Divide the mixture into bowls if using multiple colors. Add food coloring to achieve your desired colors and stir until evenly colored.
3. Layer the Fudge: Pour the colored white chocolate over the chocolate layer in the baking dish. Use a spatula to spread it evenly.

Add Toppings

1. Sprinkle Toppings: Before the fudge sets, add your favorite Halloween toppings, such as sprinkles, candy corn, or mini chocolate chips.

Cool and Cut

1. Set the Fudge: Allow the fudge to cool at room temperature for about 25 minutes. For quicker cooling, place it in the refrigerator until firm.
2. Slice and Serve: Once set, cut into squares and serve or package for gifts.