01 -
Set the oven to 350°F (175°C) and cover an 8×8 inch pan with parchment paper.
02 -
Stir together melted butter, brown sugar, and regular sugar in a big bowl until it's smooth.
03 -
Mix in the eggs one by one, then stir in the vanilla until it's all blended.
04 -
In a separate bowl, whisk flour, baking powder, cinnamon, and salt until they're evenly mixed.
05 -
Slowly add the dry mix into the wet mix, using a folding motion until just blended.
06 -
For the swirl, mix cinnamon and sugar in a small bowl. Put half the batter into the lined pan, sprinkle half the swirl mixture, add the rest of the batter, and finish with the rest of the cinnamon sugar.
07 -
Let bake for 25-30 minutes or until golden on top and a toothpick comes out clean when tested.
08 -
Whisk powdered sugar and milk until smooth. Once the blondies cool a bit, pour the glaze on top before serving.