In a LARGE microwaveable bowl add butter, peanut butter, vanilla, and 1 (10 oz.) package of mini marshmallows. Reserve the other 5 oz. of marshmallows for later.
Microwave in 45-second intervals, stirring in between with a wooden spoon or rubber spatula, until melted and gooey. Stir.
Stir in cereal, the rest of the mini marshmallows, and the peanut butter chips.
Pour mixture into a 9"x13" baking dish (lined with parchment or wax paper or sprayed with cooking spray.) Spray your hands with non-stick cooking spray or grease with a small amount of butter and press the treats into the pan.
Let stand until room temperature.
Cut into large squares.
Video
Notes
Store the treats in an airtight container or wrap them individually.I cut mine into 12 large squares, but you can easily cut them into 24 smaller squares.Stove top directions: heat butter and marshmallows in a large pot on medium to low heat until melted and smooth. Stir in cereal and mini marshmallows using a wooden spoon. Prepare the rest the same as above.