5.
In a medium-size mixing bowl, with an electric mixer on medium-high speed, beat the butter and brown sugar until well combined. Add the eggs and vanilla and beat until creamy. Scrape down the sides of the bowl and add half of the flour mixture and the milk, beating to combine. Add the rest of the flour mixture and the maple syrup, and continue to mix just until the dry ingredients are incorporated, scraping down the sides of the bowl as needed.