I got this recipe out of one of those "Holiday Cookies" magazines. The dipping-in-chocolate step, while certainly delicious, is strictly optional. I made them without the dippy part and they were absolutely great.
¾ C butter, softened
1/3 C creamy peanut butter
2/3 C sugar
1 tsp vanilla
2 C flour
2/3 C mini* chocolate chips
1 1/3 C mini* chocolate chips
2 T vegetable oil
Heat oven to 375°. Combine butter, peanut butter, sugar and vanilla in a large bowl. Beat at medium speed, scraping bowl often, until creamy. Reduce speed to low; add flour. Beat just until mixture forms a dough. Stir in 2/3 C chocolate chips by hand. Pat dough evenly into lightly greased 15" X 10" X 1" jelly-roll pan.
Bake for 12 to 15 minutes or until set and lightly browned. Immediately cut shortbread crosswise into 6 equal pieces, then cut 10 rows lengthwise. Cool completely. Remove from pan.
Place 1 1/3 C chips and oil in small microwave-safe bowl. Microwave on HIGH until almost melted (30 seconds to 1 minute). Stir until smooth. Dip one end of each cookie stick into melted chocolate; place onto wire rack over waxed paper. Let stand until chocolate is firm (1 hour).
*I used the regular-sized chips and they worked fine.