Preheat the oven to 350 F/175 C and line 2 large baking sheets with either parchment paper or silicone mats. I prefer using silicone mats.

Mix ½ cup of butter, ½ cup of brown sugar, and 3 Tbsp of granulated sugar together on a high speed for 2 minutes in a large bowl. This can be done with a stand mixer and whisk attachment or a hand mixer. I recommend setting a timer to make sure you mix it long enough! The mixture should become lighter in color as air is incorporated into it.

Next, mix in 1 large egg, 2 Tbsp of sour cream, and 1 tsp of vanilla extract on a medium speed until combined.

Sift 1 ½ cups of flour, 1 Tbsp cornstarch, 2 tsp cinnamon, ½ tsp baking soda, and ½ tsp salt into the bowl and mix on a medium-low speed just until you can no longer see streaks of flour. If you don't have a sifter, place these ingredients in a separate bowl and whisk them together before adding them into the butter / egg mixture. Scrape the sides and bottom of the bowl as needed with a rubber spatula.

Mix in ½ cup of mashed bananas and ⅓ cup of mini chocolate chips (optional) on a low speed until incorporated. The cookie batter should be a bit softer/stickier than normal cookie dough, but that's exactly how we want it to be!

Ball into 65 gram balls. Makes around 10. 6 per pan. These cookies spread a decent amount as they bake so place each cookie about 2 inches apart. If you don't have a cookie scoop, use a large spoon. Try to make the cookie dough balls as equal in size as possible so that they bake evenly.

Bake one tray of cookies at a time for 12-13 minutes and rotate the pan halfway through to help the cookies bake more evenly. Let the cookies cool on the baking sheet for 30 minutes, then transfer them to a cooling rack to finish cooling. The cookies might seem a bit soft coming out of the oven, but they will continue to bake as they cool on the pan.

Use an electric mixer to beat ½ cup of cream cheese in a medium-sized bowl until smooth.

Add in 1 ½ cups of powdered sugar and 2 tsp of vanilla extract. Mix on a low speed until combined. Scrape the sides and bottom of the bowl with a rubber spatula as needed.

Once the cookies are fully cooled, use an offset spatula or butter knife to gently spread a dollop of cream cheese frosting onto each cookie. Garnish with a sprinkle of brown sugar and a banana chip, then enjoy!

These cookies can sit at room temperature for 4 hours or be stored in an airtight container for up to a week in the fridge. I recommend letting them warm to room temperature before eating them if they've been stored in the fridge.