Mash bananas with fork to measure 1 cup. Beat brown sugar, peanut butter, margarine. Stir in egg and mashed bananas; beat to blend thoroughly.
Combine oats, flour, baking powder, salt. Stir into banana mix. Add raisins; blend well. Drop by heaping tablespoons onto greased (or coated with vegetable spray) cookie sheets. Shape cookies with back of spoon.
Bake at 375 degrees for 12 to 14 minutes, until browned. Cool on wire racks. Makes 18 large cookies.
Preparation time: 15 minutes, Baking time: 12 to 14 minutes