Preheat your oven to 350°F and line a 12-cup muffin pan with paper liners.
In a large mixing bowl, beat together the softened butter, brown sugar, eggs, vanilla extract, whole milk, and maple syrup until smooth and well combined.
In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.
Add the dry ingredients to the wet ingredients and stir just until combined, then gently fold in the chopped pecans.
Divide the batter evenly among the prepared muffin cups, filling each about ¾ full. Press a few pecan halves onto the top of each muffin.
Bake for 20 minutes, or until a toothpick inserted into the center comes out clean.
Cool in the pan for 5 minutes, then transfer to a wire rack placed over parchment paper while you prepare the topping.