Prepare the pan:

• Grease a 9×13-inch baking dish with butter or cooking spray, or line it with parchment paper for easy removal. Set aside.

Melt the marshmallows and butter:

• In a large saucepan, melt the butter over medium heat.

• Once the butter is melted, add the marshmallows to the pan and stir continuously until they are fully melted and smooth, about 3-4 minutes.

Add the Rice Krispies:

• Remove the saucepan from the heat and stir in the Rice Krispies cereal until it’s well coated with the marshmallow mixture.

Melt the chocolate:

• In a microwave-safe bowl, melt the chocolate chips in 20-30 second intervals, stirring after each, until fully melted and smooth. Alternatively, melt the chocolate using the double boiler method.

Combine the chocolate and Rice Krispies mixture:

• Pour the melted chocolate over the Rice Krispies mixture and stir until evenly combined. Add vanilla extract if desired for extra flavor.

Press the mixture into the pan:

• Pour the chocolate-coated Rice Krispies mixture into the prepared baking dish. Press the mixture firmly into the pan using a spatula or your hands (lightly greased or with wax paper) to ensure the treats hold together well.

Let the treats cool:

• Allow the treats to cool in the pan for about 30 minutes to an hour, or until they are fully set.

• Once cooled, cut them into squares or bars and serve!