Preheat your oven to 350°F (175°C).

Grease your 10-inch cast iron skillet with unsalted butter.

In a mixing bowl, cream together ½ cup butter and ¾ cup granulated sugar until light and fluffy. Add 2 eggs and 1 teaspoon vanilla extract, mixing well.

In another bowl, whisk together 2 cups flour, 2 teaspoons baking powder, and a pinch of salt. Gradually mix with wet ingredients until just combined.

Mix ½ cup brown sugar with 1 tablespoon ground cinnamon in a small bowl.

Pour half of the cake batter into the skillet, sprinkle with the cinnamon mixture, and dollop remaining batter on top, swirling together.

Bake for 25-30 minutes until golden brown and a toothpick comes out clean.

Let the cake cool for 10 minutes before serving warm with cream cheese drizzle or nuts.