Heat oven to 350°F. Spray 12-cup bundt cake pan with cooking spray with flour
In a large bowl, beat butter and brown sugar medium at speed about 2 minutes or until pale and creamy.
In a medium bowl, mix flour, baking powder and salt. In separate bowl, beat maple syrup, milk, eggs and vanilla with whisk. Add flour mixture to butter mixture in 3 additions, alternating with egg mixture. Pour batter into pan, spreading evenly with spatula.
Bake 35 to 40 minutes or until edges are golden and toothpick inserted in center comes out clean. Cool 15 minutes in pan then remove from pan and transfer to cooling rack to cool completely.
Make Glaze: In a small bowl, beat glaze ingredients with whisk until smooth. Add more powdered sugar or maple syrup if necessary for desired consistency. Spoon glaze over cooled cake, letting it drip down sides. Let glaze set at least 15 minutes before serving.