Bring a large pot of salted water to a boil. Meanwhile, peel and chop sweet potatoes into 1" cubes.
Once water is at a rolling boil, add the cubed sweet potatoes and cover with a lid. Allow to cook 5-7 minutes or until all pieces are fork tender.
Strain and dump into the bowl of a stand mixer (or alternatively a bowl for use with hand mixer). Add ½ tsp salt, 4 Tbsp melted butter, 1 tsp vanilla, ¼ cup brown sugar, 2 lightly beaten eggs, and ½ cup whole milk.
Using the whipping attachment or a hand mixer, blend the sweet potatoes for 2-3 minutes or until light and fluffy.
Pour into a greased baking dish. Cover and bake for 35 minutes at 350°F.