COMBINE, flour,oats,baking soda,baking powder,and salt in a small bowl. Set aside
BEAT margarine,peanut butter,brown sugar and splenda in large bowl with electric mixer on medium speed until light and fluffy. Add egg and vanilla mix well. Gradually add flour mixture, beating until blended. Stir in chocolate chunks.
DROP heaping tablespoon of cookie dough. 2 inches apart onto ungreased baking sheets. Flatten cookies slightly.
BAKE cookies 10 - 11 minutes or until lightly browned. Cool one minute. remove from baking sheets cool completely on wire racks.