HEAT oven to 375°F.
BEAT peanut butter and brown sugar in large bowl with electric mixer until creamy. Beat in egg, water and vanilla essence until blended. Add flour, baking soda and salt. Beat until evenly moistened. Stir in chocolate chips.
Drop by tablespoonfuls on cookie sheet. Flatten slightly in criss cross pattern with fork.
BAKE 8 to 10 minutes or until golden brown. Cool 3 minutes on cookie sheet before moving to rack to cool completely.