Step 1: Brown the butter

Place the butter in a medium saucepan over medium heat. Let it melt, then continue cooking, stirring frequently. The butter will foam before turning golden brown and developing a nutty aroma. Look for small brown specks at the bottom of the pan.

Remove the saucepan from the heat as soon as the butter is browned. Pour it into a heat-safe bowl, including the flavorful brown specks, and let it cool to room temperature for approximately 20 minutes. You can refrigerate it briefly to speed up cooling, but it should remain liquid or soft enough to mix.

Step 2: Mix the butter and sugars

In a large mixing bowl, whisk the cooled brown butter with the brown sugar and granulated sugar until the mixture looks smooth and glossy.

Step 3: Add the remaining wet ingredients

Add the egg yolk, mashed ripe banana, and alcohol-free vanilla. Whisk until everything is evenly combined.

Step 4: Combine the dry ingredients

In a separate bowl, whisk together the flour, baking soda, kosher salt, and ground cinnamon.

Step 5: Make the cookie dough

Add the dry ingredients to the wet mixture. Stir just until no dry flour remains, then fold in the chocolate chips or chunks. The dough will be soft.

Step 6: Chill the dough

Cover the bowl and refrigerate for at least 1 hour or up to 24 hours. Chilling firms the dough and helps control spreading during baking.

Step 7: Prepare the oven

When ready to bake, preheat the oven to 350°F (175°C). Line baking sheets with parchment paper.

Step 8: Scoop the cookies

Portion the chilled dough into balls of approximately 2 tablespoons each. Arrange them on the prepared baking sheets with enough space for spreading.

Step 9: Bake

Bake the Banana Bread Chocolate Chip Cookies for 10–12 minutes, until the edges are set but the centers still look soft. Avoid waiting for the centers to become completely firm; they will continue setting on the hot baking sheet.

Step 10: Pan bang, if desired

Immediately after removing the cookies from the oven, carefully tap the baking sheet on a heat-safe counter once or twice. This optional step helps create rippled edges and a slightly chewier texture.

Step 11: Add salt and cool

Sprinkle the warm cookies lightly with flaky sea salt. Let them cool on the baking sheet for 5 minutes, then transfer them to a wire rack to cool completely.