In a mixing bowl, whisk together the flour and baking powder. Set aside.
Melt the butter on the stove over medium heat. Add the sugar and brown sugar to the melted butter, and stir until combined. Then stir in the vanilla extract and salt. Allow the mixture to cool slightly, then stir in the eggs and egg yolk.
Mix the butter mixture and the dry ingredients together. Pour the batter into a greased 9x13 baking dish.
Cream Cheese Swirl: In a mixing bowl, mix the softened cream cheese, powdered sugar, vanilla, and salt together with a hand mixer or stand mixer.
Cinnamon Roll Swirl: Melt the butter and brown sugar in a small saucepan over medium heat. Remove from heat and stir in the cinnamon.
Add dollops of the cream cheese mixture and the cinnamon roll mixture evenly over the top of the blondie batter. Use a knife to swirl.
Bake at 350 degrees for 30-35 minutes until a toothpick inserted comes out clean. Allow the blondies to cool before cutting into bars.