Making the Cookies

1. Prepare the Baking Sheet

• Line a baking sheet with a silicone mat or parchment paper to prevent sticking and ensure even baking. Set aside.

2. Mix the Dough

• In a medium bowl, combine the cake mix, flour, melted butter, eggs, and sour cream.
• Use a hand mixer or mix by hand until just combined. The dough should be thick and slightly sticky. Avoid overmixing to prevent tough cookies.

3. Scoop and Chill the Dough

• Use a medium cookie scoop to create 24 even mounds of dough on the prepared baking sheet.
• Refrigerate for 1-2 hours to firm up the dough. Chilling is crucial for achieving thick, round cookies.

4. Bake the Cookies

• Preheat your oven to 350°F (175°C).
• Roll the chilled dough mounds into smooth balls and place them 2 inches apart on the baking sheet.
• Bake for 9-11 minutes, or until the edges are set and the tops begin to crack.
• Transfer to a wire rack to cool completely.

Preparing the Frosting

1. Beat the Base

• In a medium bowl, beat the softened butter and cream cheese until smooth and creamy.

2. Add Sweetness

• Gradually mix in the powdered sugar, beating until fully incorporated. The frosting should be fluffy and light.

3. Incorporate the Oreos

• Crush the Oreo cookies into fine crumbs using a Ziploc bag and rolling pin or a food processor.
• Fold the crushed cookies into the frosting until evenly distributed.

4. Transfer to Piping Bag

• Scoop the frosting into a piping bag fitted with a large round tip or a Ziploc bag with the tip cut off for easy application.

Assembling the Whoopie Pies

1. Add the Filling

• Pipe a generous dollop of frosting onto the flat side of half the cookies.

2. Create the Sandwich

• Top with the remaining cookies, pressing gently to spread the frosting evenly to the edges.

3. Serve and Store

• Enjoy immediately for the freshest flavor. Store in an airtight container:
  • At room temperature: Up to 4 days.
  • In the refrigerator: Up to 5 days.
  • In the freezer: Up to 3 months (wrap individually for best results).