In medium bowl combine melted butter, crunchy peanut butter, confectioners sugar, crushed pretzels and Ritz crackers.
Press on bottom of ungreased 9x13 dish.
Melt chocolate & 1/4 cup peanut butter in microwave at 30 sec intervals til melted. Stirring in between until melted. Pour over peanut butter/cracker mix and spread. Refrigerate for 1 hour before cutting into squares.