While the chocolate cookie crust is cooling, turn your oven to 325 degrees F.
In a medium mixing bowl, whisk together the cake flour, baking powder, and salt. Set aside.
In the bowl of a stand mixer fitted with a paddle attachment, combine the butter, oil, and sugar. Beat on medium-high speed for about 2 minutes, until light and fluffy.
Turn the mixer to medium-low and add the eggs and egg yolks, one at a time, scraping down the sides of the bowl in between each addition. Add the extracts. Turn the mixer to medium-high speed and mix for an addition 2 to 3 minutes, until the texture is smooth and the color is light.
With the mixer on low speed, alternately add the flour mixture and the sour cream, starting and ending with the flour mixture. Stir just until the flour is combined. Stop the mixer and scrape down the sides and bottom of the bowl.
In a small bowl, combine the mini chocolate chips with 1 tablespoon of flour. This helps to coat the chocolate chips so they don't sink to the bottom of the cake.
Fold the chocolate chips into the cake batter.
Evenly distribute the cake batter in the pans on top of cookie crust.
Bake for 35 to 40 minutes, until a toothpick inserted in the center of the cakes comes out with only just a few crumbs on it.
Cool the cakes on wire racks for about 10 minutes. Carefully invert the cakes onto cooking racks to cool completely. If you don't plan to stack and decorate the cake right away, wrap each layer in plastic wrap or tin foil and freeze.