Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.

In a large mixing bowl, combine 1 cup of mashed banana, ½ cup of melted butter, and ¾ cup of brown sugar. Mix until smooth.

Add in 1 egg and 1 teaspoon of vanilla extract. Whisk until fully combined.

In a separate bowl, whisk together 1 ½ cups of all-purpose flour, 1 teaspoon of baking soda, ¼ teaspoon of salt, and optional spices.

Gently fold your dry ingredients into the wet banana mixture using a spatula until the last bits of flour disappear.

Cover the dough and chill it in the refrigerator for about 20-30 minutes.

Scoop out 2 tablespoons of dough for each cookie and place them 2 inches apart on the prepared baking sheets.

Bake for 11-13 minutes until golden around the edges and slightly soft in the center.

Let the cookies cool on the baking sheets for about 10 minutes before transferring them to a wire rack.