Stir together oats and 1 T warm water, let stand for 5 minutes.

Meanwhile, stir together 1/4 cup flour, sugar, baking powder, cinnamon, and dash of salt. Stir egg yolk, oil, and milk into oat mixture; add to dry ingredients, stirring just til moistened. Fold in 5 Teaspoons of the walnuts and the raisins. Line two 6-ounce custard cups with paper baking cups. Fill 2/3rds full. Combine 1 t flour, brown sugar, butter and remaining walnuts. Sprinkle atop muffins. Micro-cook, uncovered, on 100% of power for 1 to 1 1/2 minutes or till done, rearranging once. (When done, surface may still appear moist, but a wooden pick inserted near the center should come out clean.) Remove from custard cups. Let stand on a wire rack for 5 minutes. Serve warm.