topping:
Add butter, brown sugar, and cinnamon to a 10-inch cast iron skillet over medium heat. Cook, stir frequently, until mixture starts to bubble.
Add cranberries. Cook for 5 minutes or until cranberries start to pop.
Remove from heat and set aside.
cake batter:
With an electric mixer, cream together cream cheese, butter, and granulated sugar.
Stir together buttermilk, eggs, and vanilla flavor.
Add flour and wet ingredients to creamed mixture alternately, starting and ending with dry ingredients. Only mix until all traces of flour are gone.
Pour batter over cranberry topping and spread evenly. Place skillet on top of a baking sheet to catch spills.
Bake in a 350 degree preheated oven for 55 minutes or until toothpick inserted into cake comes out clean.
Remove from oven and let cool for 5 minutes.
Invert cake onto a large platter. Let cool for 15 minutes before cutting.