Preheat oven to 350°F. Combine flour, baking soda, baking powder and salt in a small mixing bowl with a whisk or a fork. In a separate large bowl, blend butter and brown sugar with a mixer at high speed until well blended. Add eggs, one at a time, until well combined. Add vanilla and beat until combined.
In a small bowl or large measuring cup, combine beer, sour cream, and 1/4 cup of the maple syrup. Stir well with a whisk. With your mixer at low speed, add flour mixture and beer mixture alternately to the butter mixture. Make sure you begin and end with the flour mixture. Beat until just combined. Do not over-mix.
Coat a 9×5-inch baking pan with baking spray. Scrape batter into the loaf pan and bake for 40-45 minutes or until a toothpick inserted in the center comes out with crumbs clinging. Cool on a wire rack in pan for ten minutes before removing from pan and cooling completely.
Meanwhile, in a small bowl, combine powdered sugar and remaining 1 tablespoon of maple syrup, stir until smooth. Add water, a few drops at a time, as needed until a glaze consistency is reached. Drizzle glaze over cooled bread. If desired, let stand until set before slicing.