• Preheat the oven to 350°F and line a 9x13-inch baking dish with aluminum foil and set aside.

Shortbread:

• In a stand mixer fitted with a paddle attachment, cream together the butter and sugar. Add in the flour, corn starch, and salt, beating slowly at first then increasing to medium-high speed for 3 to 4 minutes until the dough pulls away from the sides of the mixing bowl and is no longer crumbly.
  1½ cups unsalted butter, ¾ cup granulated sugar, 3 cups all-purpose flour, ½ cup corn starch, 1 teaspoon salt
• Press dough evenly into the prepared baking dish and set aside.

Brownies:

• Mix brownie ingredients together according to package instructions and pour over the shortbread dough, spreading out evenly. Bake for 30 to 35 minutes.
  Fudge Brownie Box Mix, Additional ingredients required on back of box

Caramel:

• When the cookie/brownie layer is about 10 minutes from being done, add the caramels and the heavy cream to a small saucepan and melt over medium heat, stirring constantly until candies are completely melted.
  10 ounces chewy caramels, 3 tablespoon heavy cream
• Remove the cookie/brownie layer from the oven when ready and pour the caramel sauce evenly over the brownie layer. Chill in the fridge for 1 to 2 hours until caramel is stiff to the touch.

Chocolate:

• Once caramel layer has set, add chocolate chips and butter to a microwave-safe bowl and microwave for 30-second intervals until melted, stirring between each one. It usually takes 1 minute. Quickly pour over the caramel and use the back of a spoon to spread out in an even layer. Because the caramel is cold the chocolate will stiffen fast, so your need to work fast here.
  1 cup 60% bittersweet chocolate chips, 2 tablespoon unsalted butter

Peanut Butter Frosting:

• Make a half batch of my Peanut Butter Frosting and evenly spread it out over the top of the hardened chocolate layer. Sprinkle with chocolate sprinkles.
  ½ batch Peanut Butter Frosting, Chocolate sprinkles
• Gently lift the bars out of the pan by gripping the aluminum foil, I recommend picking one side of the bars to lift up while sliding the baking dish in the opposite direction so your bars are always close to the counter.
• Use a sharp knife to cut into squares for serving.