Preheat the oven to 350. In a medium sized bowl, whisk together melted butter, 2 eggs, maple syrup, brown sugar, vanilla extract, and the whole milk until combined.
To this bowl, add the oats, baking powder, cinnamon and pinch of salt. Stir together using a wooden spoon until everything is combined.
Grease a 9x9 baking pan. Add the oatmeal mixture carefully to the pan and spread it out evenly on the pan.
Bake for 25 minutes. Remove from oven when done and let cool fully. Cut into 9 bars when cool.
Once cooled, in a small bowl, mix the powdered sugar and milk together until desired consistency of glaze has been reached (for thicker, use less milk, for a thinner glaze, use more). Drizzle the glaze generously over the bars. Enjoy!