Preheat the oven to 350°F and spray a 9x9 baking dish with baking spray or grease it or line it with parchment paper to prevent the blondies from sticking to the pan.

Brown the butter by adding the butter to a small skillet and heat over medium heat.

Stir the butter occasionally as the butter begins to melt into the pan and begins to foam.

Stir constantly until little bits of brown begin to develop in the skillet. Approx. 8 minutes.

Once the brown bits begin to form, remove the butter from the heat and pour it into a large heat-proof mixing bowl to prevent the butter from browning.

Allow the butter to cool for a few minutes while you gather your other ingredients.

In the same bowl as the browned butter, beat in the granulated and brown sugar until the mixture is well combined.

Beat in the eggs and the vanilla extract just until mixed.

Add the dry ingredients: the flour, cinnamon, baking powder, and salt.

Pour the batter into the prepared baking dish, and spread it out evenly to ensure even baking.

Make the cinnamon sugar mixture by stirring the ground cinnamon into the granulated sugar until mixed evenly.

Sprinkle half of the cinnamon sugar evenly on top of the blondies batter. Reserve the rest for later.

Bake for 23-25 minutes. They will be soft in the center but the edges of the pan should be firm and browned. Avoid overbaking these blondies. They will continue to bake as they cool.

Remove them from the oven and allow them to cool.

Sprinkle additional cinnamon sugar on the bars once cooled.

Allow them to cool in the pan before slicing and serving.