Add the ingredients for the fudge to a bowl and stir together until combined (Note: ingredients will come together easier if everything is warm or melted). Taste the mixture for flavor and add more pure maple syrup to taste.
Line a loaf pan with parchment paper or foil. Pour the sweet potato fudge mixture into the lined loaf pan and spread into an even layer. Top with chopped pecans and pistachios.
Freeze the fudge at least 2 hours, until set up. Remove from freezer and cut into squares. Store fudge in a sealed bag or container in the refrigerator or the freezer. Note: fudge can be stored at room temperature for hours at a time.