Preheat oven to 350ºF. Line a 12-count muffin pan with cupcake liners.
In a mixing bowl, whisk together the flour, baking powder, baking soda, and salt until combined; set aside.
In the bowl of a stand mixer fitted with a paddle attachment, beat the butter and brown sugar together on medium speed until lightened and creamy. Beat in the eggs, one at a time, until combined, scraping down the sides and bottom of the bowl as needed. Beat in the sour cream, maple syrup, and vanilla on medium speed.
With the mixer on low speed, slowly pour the dry ingredients into the wet ingredients. Mix until just combined, scraping down the sides and bottom of the bowl as needed.
Fill cupcake liners 2/3 of the way full. Bake for 18-21 minutes or until a toothpick inserted in the center comes out clean. Allow cupcakes to cool in the pan for 5 minutes before transferring to a wire rack to cool completely.