Combine butter and cream cheese, beat until light and fluffy. Add in sugars and beat until fully combined. Mix in vanilla and one egg at a time, mixing on low
Mix Wet Ingredients
In a bowl sift together the cake flour and baking powder. Add flour mixture to the wet batter slowly. Mix until just combined. Pour batter into prepared pan and set aside.
Mix Dry Ingredients
Mix together the melted butter, cinnamon & brown sugar. Place dollops of the mixture scattered over the top of the batter, then take a knife and swirl.
Add Cinnamon Swirl
Bake the loaf, then cool completely and top with a cream cheese frosting.
Bake & Frost