Preheat the oven to 350°F (175°C). Grease a 9x13-inch baking pan and set aside.
Cream butter, granulated sugar, and brown sugar until light and fluffy. Mix in eggs, mashed bananas, vanilla, and maple extract.
Combine flour, baking soda, baking powder, salt, and cinnamon in another bowl.
Gradually mix dry ingredients into the wet mixture, alternating with sour cream. Mix until smooth.
Pour the batter into the prepared pan, spreading it evenly.
Prepare the crumb topping by combining brown sugar and flour. Cut in cold butter until crumbly, then stir in pecans. Sprinkle on top.
Bake for 40 minutes or until a toothpick comes out clean. Let the cake cool.
For the glaze, whisk powdered sugar, maple syrup, and milk until smooth. Drizzle over the cooled cake.