01 -
In a large bowl, blend the cooled melted butter with the light brown sugar until smooth and well incorporated.
02 -
Add the mashed banana to the butter mixture and mix thoroughly; then blend in the egg yolk and vanilla extract until smooth.
03 -
Stir in the salt, baking soda, and ground cinnamon until evenly combined within the wet ingredients.
04 -
Gradually add the all-purpose flour, folding gently until the batter is uniform and no dry flour remains.
05 -
Gently fold the dark chocolate chips and chopped walnuts into the dough, ensuring even distribution.
06 -
Cover the bowl and refrigerate the dough for 60 minutes to firm up and prevent excessive spreading during baking.
07 -
Preheat the oven to 175 degrees Celsius and line two large baking sheets with parchment paper.
08 -
Using a 45-gram cookie scoop, place dough balls on the baking sheets spaced at least 5 centimeters apart.
09 -
If preferred, press additional chocolate chips onto the top of each dough portion before baking.
10 -
Bake in the preheated oven for 10 to 12 minutes until edges are set and centers remain soft.