Maple Pecan Sticky Bun Coffee Cake

1. In a 9-inch cast iron skillet, melt the butter for the topping. Stir in maple syrup, brown sugar, and salt. Cook 1-2 minutes until glossy. Sprinkle pecans evenly over the bottom.
2. For the coffee cake, brown the butter if desired and allow it to cool for about 10 minutes.
3. Whisk together the butter and brown sugar. Add eggs, vanilla, and maple syrup.
4. In a separate bowl, combine flour, baking powder, and salt.
5. Add half the dry ingredients, then the milk, then the remaining dry ingredients. Mix just until combined.
6. Mix together the cinnamon swirl ingredients.
7. Spread half the batter over the pecans. Sprinkle with the cinnamon sugar. Top with the remaining batter.
8. Place a baking sheet underneath the skillet to catch any overflow.
9. Bake at 350°F for about 45 minutes. If the center is still underbaked, loosely tent with foil and continue baking for another 5-10 minutes, checking frequently.
10. Cool for 10 minutes. Run a knife around the edge, place a plate over the skillet, and carefully flip.