Prepare Bananas: Peel two medium-sized ripe bananas and mash them thoroughly in a deep bowl using a grater with bumps or a fork until they melt completely into a creamy, lump-free consistency.
Mix Sesame Seeds: Gradually add two cups of toasted sesame seeds to the mashed bananas, stirring continuously until fully integrated into a cohesive dough that can be shaped.
Shape Cookies: Using a measuring scoop, portion the dough into equal sizes. Shape each portion into thin cookies about half a centimeter thick. Use a cookie cutter and press with a pestle for uniform shapes, or simply press the dough portions flat if a cutter is unavailable. Place the shaped cookies on a baking tray lined with parchment paper without spacing them apart, as they do not expand during baking.
Bake Cookies: Bake the cookies in a preheated oven starting with lower heat at 300°F (about 150°C) for approximately 25 minutes, then switch to upper heat at the same temperature for about 5 minutes. Monitor the cookies closely to avoid burning, especially the bottoms. The goal is to dry the cookies and achieve a beautiful color and crunchy texture.
Cool and Serve: Remove the cookies from the oven once baked to a crisp golden color. Let them cool on a serving plate. Enjoy the strong banana flavor combined with the aroma of sesame.