Spray a 9x13-inch baking pan with PAM cooking spray.

Dump 1 cup of the dry Pillsbury Funfetti cake mix into a microwave-safe bowl and heat for 1 minute to heat-treat the raw flour, then let it cool.

In a large pot, melt the Land O'Lakes butter over low heat.

Add the Kraft marshmallows and stir constantly until completely melted and smooth.

Remove the pot from the heat and immediately whisk in the 1 cup of cooled, dry cake mix until perfectly smooth.

Dump the Kellogg's Rice Krispies cereal into the marshmallow mixture and fold gently with a spatula until evenly coated.

Transfer the sticky mixture into the prepared pan.

Lightly grease your hands and press the mixture firmly and evenly into the pan.

Let cool completely before cutting into squares.