1. Preheat the oven to 350°F. Butter a 9-inch square cake pan, line with foil, and butter again.
2. In a bowl, whisk the flour, baking soda, baking powder, and salt. In another bowl, whisk the sour cream and coffee.
3. Using an electric mixer, beat the butter and sugar on medium speed until pale and fluffy. Beat in the eggs, one at a time, until incorporated. Reduce the speed to low and add the flour mixture in thirds, alternating with the coffee mixture, and scraping the bowl occasionally. Pour into the prepared pan and sprinkle the cookies on top.
4. Bake until a toothpick inserted in the center comes out clean, about 40 minutes. Let cool in the pan on a wire rack. Lift out with the foil to cut into pieces. Serve warm or at room temperature.