Prepare the Baking Dish: Line an 8x8 inch baking dish with parchment paper, leaving some overhang for easy removal later. Lightly grease the parchment paper with non-stick spray.
Heat Mixture: In a medium saucepan, combine corn syrup, sugar, and a pinch of salt. Heat over medium heat, stirring constantly until the mixture comes to a gentle boil. This should take about 2-3 minutes.
Add Peanut Butter: Remove the saucepan from the heat and add the creamy peanut butter. Stir until the mixture is smooth and well combined. Then add the vanilla extract and mix until fully incorporated.
Combine with Cereal: In a large mixing bowl, place the Rice Krispies cereal. Pour the warm peanut butter mixture over the cereal and gently fold until every piece of cereal is coated evenly.
Add Chocolate Chips: Stir in 3/4 cup of the semi-sweet chocolate chips into the mixture. Allow the residual heat to slightly melt the chips, creating a gooey chocolatey texture.
Transfer to Baking Dish: Pour the mixture into the prepared baking dish. Using a spatula or clean hands (greased with a little non-stick spray), press the mixture firmly and evenly into the dish.
Melt Remaining Chocolate: In a microwave-safe bowl, melt the remaining 1/4 cup of chocolate chips in 20-second intervals, stirring between each, until smooth.
Drizzle Chocolate: Once melted, drizzle the chocolate over the pressed Rice Krispie treat mixture. Let it spread slightly if desired for a marbled effect.
Chill: Allow the treats to cool at room temperature for 20 minutes, then transfer to the refrigerator and chill for at least 1 hour to set.
Slice and Serve: Once set, lift the treats out of the baking dish using the parchment overhang and cut them into squares. Enjoy!
Notes
For a marbled effect, let the chocolate drizzle spread slightly.