Beat the softened butter until light and creamy.

Add the light brown sugar and granulated sugar, then beat until smooth and fluffy.

Add the vanilla extract and mix until well combined.

Add the Biscoff cookie butter spread .

Add the mashed banana and mix until fully incorporated.

Continue beating until the wet ingredients are smooth and well combined.

In a separate bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt.

Gradually add the dry ingredients to the wet ingredients and mix until just combined.

Continue mixing until a soft cookie dough forms with no dry flour remaining.

Scoop equal portions of dough onto a parchment-lined baking sheet, leaving about 2 inches between each cookie.

Bake at 350°F (175°C) for 10–12 minutes, or until the edges are lightly golden. Let the cookies cool completely.

Spread the Biscoff cookie butter over each cooled cookie and serve.