Creative Variations for Your Banana Cookie

In a medium bowl, whisk together the all-purpose flour, baking soda, and kosher salt. Set aside.

In a large bowl, whisk the melted butter and brown sugar until fully combined and smooth. There should be no lumps.

Add the egg, egg yolk, and vanilla extract to the sugar mixture. Whisk vigorously for about 30 seconds until the mixture is glossy and slightly lightened in color.

Stir in the mashed banana until just incorporated.

Pour the wet ingredients into the dry ingredients. Mix with a spatula until just combined; do not overmix. A few streaks of flour are perfectly fine. This is the key to a tender cookie.

If adding mix-ins (see variations below), gently fold them in now.

Cover the bowl with plastic wrap and chill the dough in the refrigerator for at least 30 minutes, or up to 2 hours. This prevents spreading and deepens the flavor.

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

Scoop rounded tablespoons of dough (about 1.5 tbsp each) onto the prepared baking sheets, leaving about 2 inches of space between them.

Bake for 11-13 minutes, or until the edges are golden brown and the centers are set. They might look slightly underdone in the middle, but they will continue to cook on the pan.

Let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.