Stepwise Method:

• Line a 9x9-inch baking pan with parchment paper, leaving some overhang on the sides for easy removal later. Preheat your oven to 350°F (175°C).
• In a mixing bowl, beat together 1/3 cup of room temperature unsalted butter and 1/3 cup of granulated sugar until creamy. Stir in 1/2 teaspoon of vanilla extract. Gradually add 1 cup of all-purpose flour and 1/4 teaspoon of salt, mixing until a crumbly dough forms. If the dough seems too dry, add 1 tablespoon of whole milk.
• Press the shortbread mixture evenly into the bottom of the prepared baking pan. Bake in the preheated oven for 20-25 minutes, or until the edges are lightly golden. Remove from the oven and let it cool slightly.
• In a saucepan over low heat, combine 7 oz. of caramel bits (or soft caramel candies), 2 tablespoons of whole milk, and 2 tablespoons of sweetened condensed milk. Stir until the caramels are fully melted and smooth. Once melted, pour the caramel over the cooled shortbread layer, spreading it evenly.
• In a small bowl, mix together 3 tablespoons of creamy salted peanut butter and 1/2 cup of coarsely chopped peanuts. Sprinkle the peanut butter mixture over the caramel layer, spreading it gently to create an even layer.
• In a double boiler or microwave-safe bowl, combine 5 ounces of finely chopped dark or bittersweet chocolate, 1/2 cup of heavy cream, and 1 tablespoon of corn syrup. Heat gently, stirring until the chocolate is melted and the mixture is smooth. Pour this chocolate ganache over the peanut butter layer, spreading it evenly.
• Refrigerate the bars for at least 2 hours, or until the chocolate is set. Once set, lift the bars out of the pan using the parchment paper overhang. Cut into squares or rectangles and serve. Enjoy your Peanut Butter Millionaire Shortbread Bars!