Pour boiling water over oats; let stand 30 minutes. Stir to together flour, cinnamon, baking powder, baking soda, and salt; set aside. In medium bowl cream butter with sugars until fluffy. Beat in eggs one at a time, then vanilla. Stir in flour mixture, oats, walnuts, coconut, and raisins until blended. Spoon into 1 1/2 inch muffin tins lined with paper muffin cups; place a walnut half on each.
Bake in preheated 350-degree oven 20 to 25 minutes or until pick inserted in center comes out clean. Remove from pans; serve warm or at room temperature. Makes 30.