Heat and prep: Position a rack in the center and heat oven to 350°F; butter a 9×5-inch loaf pan and line with parchment with 2-inch overhang.
Cream the butter and sugars: Beat softened butter with both sugars on medium-high ~3 minutes until pale and fluffy.
Add the eggs and banana: Beat in eggs one at a time, then vanilla; mash bananas and fold in.
Whisk the dry ingredients: Whisk flour, baking powder, baking soda, cinnamon, salt in a separate bowl.
Fold, don't stir: Add dry mix in two additions, fold gently just until no dry streaks remain.
Add the mix-ins, top and bake: Fold in chocolate chips and pecans; scrape into pan; press banana halves cut-side up into surface; sprinkle brown sugar; bake 55–65 min until a skewer comes out clean.
Glaze and cool: Brush maple syrup over the hot loaf; cool 15 min in pan, lift out, cool completely on a wire rack.