Cut the sweet potatoes into 1" chunks and place them in a large mixing bowl.
Combine the rest of the ingredients, except for the parsley, in a small measuring cup or mixing bowl and whisk vigorously with a fork until well combined. Pour over the cubed sweet potatoes and toss gently until evenly coated.
Spread the sweet potatoes in a single layer onto a dark roasting pan and bake in the preheated oven for 35 to 40 minutes or until tender and golden brown, stirring once about halfway through cooking.
Sprinkle with a handful of chopped parsley, if desired, and serve.