Skillet Sweet Potatoes with Toasted Pecans

½ cup light brown sugar

¼ cup granulated sugar

1 teaspoon ground cinnamon

1 teaspoon ground nutmeg

1 pinch kosher salt

½ cup unsalted butter

6 sweet potatoes, peeled and sliced into 1/3” rounds

2 teaspoons vanilla extract

¾ cup pecans, chopped and toasted