Preheat oven to 375 degrees.
Using a knife, carefully poke holes in each potato. Roast potatoes for 50-60 minutes, flipping halfway through. Potatoes are done when tender and skin is beginning to wrinkle and separate from the potato flesh.
Let potatoes cool slightly before peeling skin off – they will be VERY hot! Add potatoes to a blender along with salt, vanilla, butter, and cream cheese, if using. Blend for 1-2 minutes, or until completely smooth and fluffy.
Heat a small saucepan on low. Add nuts, syrup, cinnamon, and salt and sauté for 1-2 minutes, stirring frequently, being careful not to burn.
Remove from heat. Let cool in a single layer on parchment paper.
Cream cheese is a delicious addition but is not necessary for a tasty mash. It adds a luscious, slightly cheesecake-y touch without being too heavy.