Prepare the baking dish by greasing it or lining with parchment paper.

In a medium saucepan, combine the granulated sugar and light corn syrup. Heat over medium heat until the mixture boils, stirring constantly.

Remove from heat and stir in the creamy peanut butter until smooth.

Add the mini marshmallows and stir until melted and combined.

In a large mixing bowl, add the Special K cereal and pour the peanut butter mixture over it. Mix until fully coated.

Transfer the mixture to the prepared baking dish and press down firmly.

Let it cool at room temperature for about 30 minutes.

Once cooled, cut into squares or rectangles and serve.