8tablespoons1 stick unsalted butter, at room temperature
1/2cupgranulated sugar
1/2cuppacked light-brown sugar
1large egg, at room temperature
1/4teaspoonvanilla extract
1/4teaspoonbanana extract
For the Peanut Butter Cream Cheese Filling:
1 8-ozpackage cream cheese, at room temperature
8tablespoons1 stick unsalted butter, at room temperature
1/2cupsmooth peanut butter
1 ½cupspowdered sugar
Instructions
Preheat oven to 350 F. Line 2 baking sheets with parchment paper.
Whisk the flour, baking powder, baking soda and salt together in a medium bowl; set aside.
Combine the banana and sour cream in a measuring cup and set aside.
In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and both sugars on medium speed until pale in color and fluffy, about 3-4 minutes. Scrape down the sides of the bowl, then add the egg, vanilla extract and banana extract, beating until incorporated. Alternately add the flour mixture (in 3 additions) and banana mixture (in 2 additions), starting and ending with the flour mixture. Beat only until ingredients are just combined.
Drop by heaping tablespoons onto the prepared baking sheets, about 2-inches apart. Bake, one baking sheet at a time, until edges are golden brown and the cakes spring back when gently pressed, about 10-12 minutes. Remove from oven and slide the parchment paper, with the cakes, onto a wire rack to cool completely. Use a thin metal spatula to lift the cookies off the parchment paper.
To make the filling: In the bowl of a stand mixer fitted with the paddle attachment, beat together the cream cheese, butter, and peanut butter, on medium speed until the mixture is smooth and fluffy, about 1 minute.
Add the confectioners’ sugar and the vanilla and beat on low until incorporated. Increase mixer speed to medium and beat until fluffy, about 2 minutes more.
To assemble, turn half of the cooled cookies upside down, flat side facing up. Drop a large dollop of filling onto the flat side of the cookie, leaving a 1/4-inch plain edge.
Place another cookie, flat side down, on top of the filling. Press down slightly so that the filling spreads to the edges of the cookie.