Preheat the oven to 350°F (180°C) and grease a 9x5-inch loaf pan. Line the pan with a strip of parchment paper leaving an overhang to easily lift out the bread.
Combine flour, baking soda, salt, and cinnamon. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and sugar together for about 4 minutes until light and fluffy.
Add eggs, one at a time, mixing 20 seconds after each addition.
Add vanilla extract and yogurt, mix until incorporated.
Add mashed bananas and mix until combined.
With a rubber spatula, mix in the flour mixture until just incorporated and no flour pockets remain. Fold in the nuts and transfer the batter to the prepared pan.
Make the topping: In a small pan, melt butter over medium heat. Stir in honey (or maple syrup) and whisk to combine. Add chopped walnuts and cook for 1-2 minutes, stirring constantly, until the mixture thickens.
Distribute the topping evenly on top of the batter.
Bake for 55-65 minutes or until a toothpick inserted into the center of the bread comes out clean. Cover pan with aluminum foil after 30 minutes.
Let the bread cool in the pan on a cooling rack for 5-10 minutes. Then lift the bread out of the pan and let cool completely on the rack.