Although these bar cookies look like a typical blondie recipe, they're made with peanut butter. The frosting is melted white chocolate chips.
Heat oven to 350 degrees F. Line a 13 x 9 x 2-inch baking pan with foil, extending over two sides.
In a medium-size bowl, whisk together the flour, baking powder and salt. Set aside.
In a large bowl, beat butter and peanut butter for 1 minute, until blended. Add sugar; beat for 2 minutes, until smooth. Beat in vanilla. Add eggs; beat until smooth, about 1 minute.
Stir in flour mixture and 3/4 cup of the nuts.
Spread batter evenly into pan. Bake at 350 degrees F for 30 minutes until toothpick inserted in center comes out clean. Remove from oven. Immediately sprinkle white-chocolate chips over top. Let stand 5 minutes until chips are soft enough to spread. Spread chocolate over top; sprinkle on remaining 1/4 cup chopped nuts.
Cool in pan on wire rack. When cool, remove from pan and gently peel away foil. Cut into 18 bars.