Chocolate Chip Cookie Layer Cake

release from the pans. If its helpful see this parchment paper rounds for cakes video post.
Make the cookie cake Whisk the flour cornstarch baking soda and salt together in a medium bowl. Set aside.
In a large bowl using a hand mixer or a stand mixer fitted with a paddle attachment beat the butter brown sugar and granulated sugar together on mediumhigh speed until smooth and creamed about 2 minutes. Add the eggs and vanilla extract and beat on high speed until combined about 1 minute. Scrape down the sides and up the bottom of the bowl and beat again as needed to combine.
Add the dry ingredients to the wet ingredients and mix on low until combined. With the mixer running on low speed beat in the chocolate chips. Dough will be thick and sticky.
Divide cookie dough between however many cake pans youre using. Press evenly into each. I only have 3 6inch cake pans so I baked in batches. If baking in batches cover any cookie dough that isnt being used and set aside at room temperature.
Bake for 2022 minutes or until the cake layers are lightly brown on top and a toothpick inserted in the center comes out mostly clean. Allow cakes to cool for 10 minutes in the pans. Run a sharp knife around the edges then carefully invert the pan so the warm cookie cake slides out. At this point you can clean out pans grease line with parchment grease parchment then bake remaining cakes if needed. Set the baked cakes on a wire rack to cool completely. The cakes must be completely cool before frosting and assembling
Make the frosting  With a handheld or stand mixer fitted with a paddle or whisk attachment beat the butter and peanut butter together on medium speed until creamy and smooth about 2 minutes. Add confectioners sugar cocoa powder vanilla extract and 1 Tablespoon milk. Mix on low speed for 30 seconds then increase to high speed and beat for 2 minutes. Add another Tablespoon or 2 of milk if frosting is too thick. Taste and add a pinch of salt if needed. I always add a pinch!
Assemble and decorate Place 1 cake layer on your cake stand cake turntable or serving plate. Evenly cover the top with frosting. Continue layering the cake layers and frosting. Spread the remaining frosting all over the top and sides if theres any leftover for the sides! If desired top with
chocolate chips. Slice and serve.
Cover leftover cake tightly and store in the refrigerator for 5 days