Peanut Butter Cup Cookie Cake

1. Preheat oven to 350°F. Line the bottom of the springform pan with parchment paper or lightly grease with butter.
2. Bring butter and eggs to room temp. The butter is ready when a light imprint can be left in the stick of butter with your thumb. To soften faster, slice into chunks.
3. Measure flour by weight for best results. No scale? First fluff the flour with a spoon then gently spoon it into a dry measuring cup. Use a butter knife or bowl scraper to scrape the excess so its level with the top edge of the measuring cup.
4. In a medium-large bowl, whisk together flour, cornstarch, baking soda, and salt. Set aside.
5. Cream together softened butter and both sugars in a stand mixer with the paddle attachment. Start at the lowest speed and increase as needed for 2 minutes.
6. Add in the egg and vanilla and continue to beat with the mixer to incorporate into the dough, approx. 30-45 seconds.
7. Add flour mixture to the larger bowl slowly while you continue to beat on low.
8. Once dough is mixed (taking care not to over-mix), use the beater to mix or fold in chocolate chips and peanut butter chips.

READY TO BAKE?

1. Break off chunks of dough and arrange in the pan. Press together to create an even layer of cookie dough in the pan. Press some extra chocolate chips into the top of the dough before baking.
2. Place the pan on the center rack of the oven and bake at 350°F for 16-17 minutes until the dough has fluffed up and is just slightly starting to darken in color.
3. Remove from oven and place on a wire cooling rack. Press some mini peanut butter cups into the top of the cake then allow cookie cake to completely cool. You can remove the springform ring (the sides) to help it cool faster. It should be set and cool enough to frost after one hour. While it cools, make your frosting and plan for the fun part – the decorating!

MAKE THE FROSTING

1. In the bowl of a stand mixer fitted with the paddle attachment or in a large mixing bowl using a handheld mixer, beat the softened butter and peanut butter until smooth and creamy, scraping down the sides as needed. (approx. 1-2 minutes)
2. Add the powdered sugar and mix on low speed at first to incorporate then increase to medium speed and continue mixing for an additional 1-2 minutes or until fully combined. Add the heavy cream (or milk), vanilla extract, and salt and continue mixing on medium speed until everything is well-combined, smooth, and easy to pipe.
3. Transfer to piping bags (disposable or reusable) fitted with assorted star tips to create cute starburst designs. Soft sprinkles and extra peanut butter cups can be added on top if you'd like – have fun with it!
4. NOTE: If desired reserve a portion of the peanut butter buttercream frosting to make some chocolate PB frosting. You can use dutch-processed unsweetened cocoa powder (a bit more intense chocolate flavor) or regular unsweetened cocoa powder. Add a tablespoon at a time and blend into the frosting until incorporated. Give it a little taste test and add any extra cocoa powder desired.

ADVANCE PREP INSTRUCTIONS

1. I almost always make my dough in advance, it's such a time saver! Place prepared dough on a large sheet of plastic wrap and wrap securely *OR* place in a shallow airtight container with a lid. Refrigerate overnight or 1-3 days for make-ahead dough for your cookie cake. I find that the flavors and textures are amazing when I do this! When ready to bake, allow dough to soften on the counter for an hour until scoopable.
2. When your ready to bake, preheat oven and line the bottom of your nonstick springform pan with parchment paper for super easy cookie removal. Break off chunks of the dough and arrange in the pan, then press down into a smooth and even layer. I like to sprinkle a few extra chocolate chips on top before baking, then press my mini peanut butter cups in right after baking so they hold their shape.
3. The frosting can be made in advance and stored in the fridge for up to a week. Bring back to room temp and lightly mix before adding to a piping bag to decorate.