HEAT oven to 375ºF.
MIX flours, sugar, baking powder and salt in large bowl. Cut in peanut butter and margarine with 2 knives or pastry blender until mixture resembles coarse crumbs. Add milk and eggs; stir just until dry ingredients are moistened. (Batter will still be lumpy.)
SPOON into 12 paper-lined muffin cups.
BAKE 15 to 18 min. or until toothpick inserted in centres comes out clean. Cool in pan 5 min. Remove to wire rack; cool completely.
