Pre-heat oven to 350 F. Line a 9″ x 13″ pan with aluminum foil. Grease pan. Set aside.
Cream Baker’s Best margarine and brown sugar. Add eggs one at a time, beating well after each addition. Add vanilla. Combine flour and baking soda. Add to mixture. Fold in oatmeal. Press 3/4 of this mixture at the bottom of the prepared pan.
Melt chocolate in a double boiler. Blend condensed milk. Set aside.
Spread drained crushed pineapple over crust. Add chocolate mixture and dot with remaining oatmeal mixture. Bake for 25 – 30 minutes. Cool and cut into bars.