1. Preheat oven to 350°F. Grease a 9×13-inch baking pan.

2. In a large bowl, cream softened butter and sugar until fluffy.

3. Beat in eggs one at a time, then mix in vanilla extract.

4. Alternate adding flour and buttermilk, mixing until batter is smooth.

5. In a separate bowl, combine melted butter, brown sugar, and cinnamon for the swirl.

6. Pour half the batter into the pan, spoon in half the cinnamon mix, and swirl lightly.

7. Add remaining batter and swirl in the rest of the cinnamon mixture.

8. Bake for 30–35 minutes or until a toothpick comes out clean.

9. While warm, poke holes all over the cake and pour in remaining cinnamon butter mixture.

10. Let cake cool fully.

11. Beat cream cheese, butter, powdered sugar, and vanilla until smooth.

12. Frost the cooled cake and chill slightly before slicing if desired.