In large mixing bowl, with electric mixer, cream together butter and sugar until fluffy. Beat in maple flavouring and vanilla. Stir in pineapple and juice.
In separate bowl, mix together flour, milk powder, baking soda, cinnamon and salt. Stir dry ingredients into pineapple mixture. Stir in oatmeal, raisins and walnuts until well combined.
Drop by rounded spoonfuls onto greased baking sheet. Bake in 350°F (180°C) oven for 12 to 15 minutes or until golden brown. Cool on baking rack.