Make early on day:
1. In large bowl, with mixer at medium speed, beat sugar, butter, egg, and vanilla until well blended. Now beat in chocolate.
2. Start heating oven to 350Â°F.
3. Sift flour with baking powder; beat into sugar mixture alternately with evaporated milk. Stir in 1 cup nuts. Pour into greased 9-by-9-by-2-inch baking dish; sprinkle with rest of nuts.
4. Bake 30 minutes, or until cake tester, inserted in center, comes out clean.
5. Cool in pan on wire rack. Cover with foil; store at room temperature. When ready to serve, cut into 16 squares.