Heat oven to 350°F. Line two cookie sheets with aluminum foil. In large bowl, combine oats, flour and baking powder. Add butter; beat on low to medium speed of electric mixer until crumbly. Add sugars, water and vanilla. Beat on low speed until dough starts to form. By hand, stir in peanuts. Divide dough in half. Place half on one cookie sheet; flatten with lightly floured hands into 13 x 9-inch rectangle. Repeat using remaining dough and second cookie sheet. Bake 22 to 25 minutes or until golden brown, rotating cookie sheets after 12 minutes. Place cookie sheets on wire racks. Sprinkle 1 cup chocolate chips evenly over each large cookie. Let stand 2 to 3 minutes. With spatula or knife, spread softened chocolate evenly over cookies. Cool completely. (Refrigerate 15 minutes to set chocolate, if necessary). Remove large cookies from cookie sheets and peel off foil. Break each large cookie into 24 pieces. Store tightly covered.