1/2 cup powdered sugar
1 teaspoon vanilla
1 1/4 cups all-purpose flour
1/4 cup unsweetened cocoa
1/2 teaspoon baking powder
1/3 cup finely chopped dry roasted peanuts
Combine butter, powdered sugar and vanilla in large bowl; beat at medium speed until creamy. Reduce speed to low; add flour, cocoa and baking powder. Beat until well mixed.
Divide dough in half. Shape each half into 6-inch log. Place chopped peanuts into pie pan or large shallow bowl; roll each log in peanuts to coat. Wrap each in plastic food wrap. Refrigerate until firm (at least 2 hours).
Heat oven to 400°F. Cut logs into 1/4-inch slices with sharp knife. Place 1 inch apart onto ungreased cookie sheets. Bake for 7 to 9 minutes or until set. Remove immediately to wire cooling rack.
Pulse peanuts in a food processor for quick finely chopped nuts.