Cream butter in a large mixing bowl; gradually add sugar, beating until light and fluffy. Add eggs, one at a time, beating well after each addition.
Combine 3 1/2 cups flour and baking powder; gradually add to creamed mixture alternately with lemon extract, beginning and ending with flour mixture. Beat well after each addition (batter will be thick). Dredge pecans and raisins in remaining 1/2 cup flour; stir into batter.
Spoon batter into a greased and floured 10 - inch tube pan. Bake at 325° for 1 hour and 30 minutes or until cake tests done. Cool in pan 15 minutes; remove, and let cool completely before serving.