Melt the butter in a medium-sized saucepan. The butter will start to foam and you will see orangey-brown bits form at the bottom of the pan. This will take about 5 minutes.
Remove from heat and allow to cool.
Preheat oven to 350 degrees (F). Spray your donut mold with non-stick spray and set aside.
In a medium-sized bowl whisk together the flour, light brown sugar, salt, and baking powder.
In a separate bowl mix the wet ingredients together. Gently fold the wet ingredients into the dry ingredients.
Spoon the batter into the donut pan. Bake the donuts into the pre-heated oven and bake for 20-25 minutes or until they spring back when lightly pressed.
Remove from oven and allow to cool in the pan for 10 minutes and then remove from pan and allow to cool completely before glazing.
For Glaze:
In a small bowl combine all of the ingredients and whisk until free of lumps.