Preheat oven to 425 degrees. Place butter in a 9x13 pan in the oven. While the butter is melting, mix the remaining ingredients in a blender. Once butter is melted, bubbly, and slightly browned, pour batter into pan and bake for 15-20 minutes at 425 degrees.
Serve with powdered sugar on top, then squeeze some fresh lemon juice on top.