If you have a slow stove, put a pot of boiling water on that you can fit a metal or glass bowl on top of before starting.
In a medium bowl, (or food processor as I did) mix together 3/4 cup of melted butter or margarine, graham cracker crumbs, confectioners' sugar, and 1 1/4 cup peanut butter until well blended. Press evenly into the bottom of a greased 9x13 inch pan. Refrigerate this crust for 20-30 minutes. After the crust has been in the fridge about 15 minutes, start your chocolate mixture.
In a metal or glass bowl over simmering water melt the chocolate chips, 1/4 cup of melted butter and 5 tablespoons of peanut butter, stirring occasionally until smooth. Spread over the refrigerated crust. I find if you spread it immediately with the back of a spoon it works perfectly! Refrigerate for at least one hour before cutting into squares.