Lydia found this recipe in Grace's Williams-Sonoma Cookbook for Kids. I am a sucker for chocolate and peanut butter!
1/2 cup butter at room temperature
3/4 cup brown sugar
1/4 cup white sugar
3/4 cup peanut butter
1 large egg
1/2 teaspoon vanilla
1 1/4 cups all-purpose flour
1 teaspoon baking soda
1/4 teaspoon salt
1 1/2 cups semi-sweet chocolate chips
1 1/2 tablespoons vegetable shortening
Preheat oven to 350 degrees. Line baking sheets with parchment paper. In large bowl, beat the butter, brown sugar, white sugar, and peanut butter with electric mixer on medium speed until blended. Add the egg and vanilla and beat until blended. Add the flour, baking soda, and salt and beat on low speed until blended. Shape the dough into 1 1/2 inch balls, placing 12 balls at least 2 inches apart on the baking sheet. Dip fork in flour and press each cookie twice to make a criss-cross pattern. Bake until golden, about 8-10 minutes. Let the cookies cool on the pans for five minutes, then transfer to wire racks to cool completely. Meanwhile, add the chocolate chips to a microwave-safe bowl. Add the shortening. Microwave on high for one minute, stir, then microwave again for 30 seconds longer or until melted. One at a time, dip half of each cookie into the chocolate, then place on a baking sheet lined with parchment paper. Place the cookie sheet in the refrigerator just until the cookies set, about five minutes. Store in an airtight container at room temperature for up to five days. Makes 24 cookies.