Start by lining your 9x13-inch baking pan with parchment paper. This will help you remove the bars easily once they’re set.
In a large mixing bowl, combine the creamy peanut butter, corn syrup, granulated sugar, light brown sugar, and vanilla extract. Mix until the ingredients are thoroughly combined and smooth.
Gently fold in the Special K cereal until it is evenly coated with the peanut butter mixture. Make sure every piece is covered for maximum flavor.
Transfer the mixture to the prepared baking pan. Use a spatula or your hands to press it down firmly and evenly into the bottom of the pan.
In a double boiler or microwave-safe bowl, melt the semi-sweet chocolate chips until smooth. If using a microwave, heat in 30-second intervals, stirring in between to prevent burning.
Once the chocolate is melted, stir in your chosen bite-sized candy bar pieces. This adds an extra layer of fun and flavor to your bars.
Pour the chocolate and candy mixture over the peanut butter base in the pan. Use a spatula to spread it evenly across the top.
Place the baking pan in the refrigerator for about 1-2 hours or until the chocolate has fully set. This will help the bars hold their shape when cut.
Once set, lift the bars out of the pan using the parchment paper. Cut into squares or rectangles, and enjoy your delicious Chocolate Peanut Butter Candy Bars!