Peanut Butter Fudge Brownie Bars

1 1/2 cup butter or margarine, melted, divided
1 1/2 cups sugar
2 eggs
1 teaspoon vanilla extract
1 1/4 cups all-purpose flour
2/3 cup baking cocoa
1/4 cup milk
1 1/4 cups chopped pecans, divided (optional)
1 pkg. (10oz) peanut butter chips
1 can (14 oz) sweetened condensed milk
1/4 cup semisweet chocolate chips

In a large bowl, combine 1 cup melted butter, sugar, eggs and vanilla; beat well. Add flour, cocoa and milk; beat until blended. Stir in 1 cup pecans. Pour into a greased 13x9 baking pan. Bake at 350 for 25-30 minutes or just until edges begin to pull away from sides of pan. Cool completely in pan on wire rack. In a medium saucepan over low heat, combine remaining butter and peanut butter chips, stirring constantly. Stir in sweetened condensed milk until smooth; pour over baked layer. Place chocolate chips in a small microwave-safe bowl. Microwave on high for 45 seconds; stir. If necessary, microwave an additional 15 seconds at a time, stirrring after each heating, just until chips are melted. Drizzle bars with melted chocolate; sprinkle with remaining pecans. Refrigerate 1 hour or until firm. Cut into bars. Yield 2 dozen.