Line a 9-inch by 13-inch pan with parchment paper.
Add the marshmallow creme, German sweet chocolate, chocolate chips, and walnuts to a large heat-safe bowl. Set it aside.
In a large, heavy saucepan, melt the butter on medium heat.
Pour the evaporated milk and sugar into the pan and mix until combined.
Cook on medium-high. Bring to a boil and boil for six minutes, stirring often.
After six minutes, pour the boiling syrup over the chocolate mixture and mix until combined.
Pour fudge into the pan and sprinkle a handful of walnuts on top.
Allow the fudge to set up for two to three hours at room temperature or one to two hours in the refrigerator.
Once it sets up you can lift fudge out with the parchment paper.