1-First, line a 9-inch by 13-inch baking dish with parchment paper to make removal easy later. In a large heat-safe bowl, combine 370 grams marshmallow cream, 340 grams broken sweetened baking chocolate pieces, 340 grams semi-sweet chocolate chips, and 2 cups chopped walnuts, then set it aside.

2-Next, in a large heavy saucepan, melt 2 tablespoons salted butter over medium heat before adding 340 grams evaporated milk and 4 and 1/2 cups sugar; stir until combined.

3-Increase the heat to medium-high and bring the mixture to a boil, stirring often for exactly six minutes this step is crucial for a smooth texture. Once boiling, pour the hot sugar mixture over the bowl with the chocolate and walnut mix, and stir until everything is fully combined to form that perfect creamy fudge. Pour the fudge into your prepared pan and sprinkle extra walnuts on top for added crunch.

4-Let the fudge set at room temperature for two to three hours, or pop it in the fridge for one to two hours if you’re in a hurry. Once it’s firm, lift it out using the parchment paper and cut it into 1-inch squares for serving. For dietary adaptations, refer back to the ingredients section for options like vegan swaps. Preparation takes about 15 minutes, cooking is around 10 minutes, and setting time is 2 to 3 hours, making the total time approximately 3 hours and 25 minutes.