Banana bread muffins

Ingredients

• 5 bananas
• 3 1/2 oz walnuts
• 1/2 cup brown sugar
• 2 eggs
• 1 stick butter (melted)
• 1 tsp vanilla extract
• 1 1/4 cups flour
• 3/4 cup ground hazelnuts
• 1 tsp baking soda
• 1 tsp baking powder
• 1/4 tsp sea salt
• 1/2 cup chocolate chips (optional)