Sift together flour, sugar, cocoa, baking powder and salt. Add milk, salad oil, and vanilla; mix until smooth. Stir in nuts.
Pour into greased 8x8x2 inch pan. Mix together brown sugar and 1/4 cup cocoa; sprinkle over batter. Pour hot water over entire batter.
Bake at 350° For 45 minutes. Do not overbake. It will be jiggly when you take it out - that's the "pudding" underneath.
Serve warm or cold with ice cream or Cool Whip.
Servings: 6 - 8