Peanut Butter Bars
["1/4 c. margarine", "1/4 c. peanut butter", "1 1/3 c. brown sugar, packed", "2 eggs", "1 1/2 c. flour", "1 1/2 tsp. baking powder", "1/2 c. chocolate chips", "1/2 c. finely chopped nuts (optional)"]
["Cream the margarine and peanut butter.", "Add brown sugar and mix well.", "Add eggs and mix until well blended.", "Stir in dry ingredients until blended, then chips and nuts.", "Spread batter in greased and floured 9-inch pan.", "Bake at 350\u00b0 for 30 to 35 minutes.", "Cool in pan.", "Cut, when cool, into 36 bars."]
["margarine", "peanut butter", "brown sugar", "eggs", "flour", "baking powder", "chocolate chips", "nuts"]