In a saucepan over low heat, cook and stir peanut butter and butter until blended. Stir in marshmallows until melted. Remove from the heat; fold in pecans.
Break or cut each graham cracker into four pieces. Spread with peanut butter mixture; top with remaining crackers. Spread candy coating over both sides. Line a baking sheet with lightly greased waxed paper; place crackers on waxed paper; place crackers on waxed paper and chill until firm.
Editor's Note: Confectionery coating is found in the baking section of most grocery stores. It is sometimes labeled "almond bark" or "candy coating" and is often sold in bulk packages of 1 to 1-1/2 pounds.