1Preheat oven to 350 degrees F (175 degrees C). Grease a 11 x 7 inch baking pan.
2In a large bowl, beat peanut butter, shortening, and sugar until light and fluffy. Beat in eggs, water, and vanilla until smooth. Combine flour, baking powder, and salt; stir into peanut butter mixture until combined. Stir in chocolate pieces. Spread dough into prepared pan.
3Bake for 40 minutes, until golden brown. Cool in the pan on a wire rack. Cut into bars.