In a saucepan over medium heat, melt the butter. Cook butter, whisking frequently. Watch butter carefully – remove from heat as soon as butter begins to brown and smells nutty. Place butter in the bowl of a stand mixer.
Add brown sugar and mix well. Add baking powder, salt, vanilla, and cinnamon and mix well again. Gradually add flour. Finally, add eggs and mix until well-incorporated.
Spoon into 9×13 pan. Bake for 30 minutes. Sprinkle with powdered sugar before serving, if desired.
Notes
Adapted from Penzey’s.
Recipe by Not Your Momma’s Cookie at https://notyourmommascookie.com/2013/11/browned-butter-brown-sugar-bars/