Line a baking sheet with parchment paper and preheat the oven to 350°F (175°C).
Toast the sesame seeds in a pan over low heat for a few minutes, stirring often, until fragrant. Be careful not to burn them.
Mash the ripe bananas with a fork in a bowl until smooth. Add the toasted sesame seeds and mix until combined.
Drop a tablespoon of dough onto the baking sheet and use a spoon to shape it into a round. Press the back of the spoon in the center to create an indentation.
Bake for 15 minutes, then let the cookies cool completely.
Melt the chocolate chips with peanut butter in a microwave-safe bowl, using 30-second intervals, stirring after each until smooth.
Pour a spoonful of the melted chocolate mixture into each cookie’s indentation. Let them set for a few minutes before serving.