Cocoa Krispies Treats

I've been making these for years, and have no idea where I got the recipe. It may have come off the back of a Cocoa Krispies box.  But we like these better than regular Rice Krispies Treats. The addition of peanut butter makes them a little better, in my opinion.

Cocoa Krispies Treats

1 small box Cocoa Krispies (store brands work fine, too)
1 small bag miniature marshmallows
3 tablespoons butter or margarine
1/3 cup peanut butter

Pour the Cocoa Krispies into a large bowl. Lightly butter a 13" x 9" pan. In a medium saucepan over medium-low heat, melt together the marshmallows, butter, and peanut butter.  When all the marshmallows have melted, pour the mixture over the Cocoa Krispies. Stir quickly to combine; pour out into buttered pan. Get your hands damp with water, and press the mixture down into the pan to even it all out.  Let cool and then cut into bars.