Heat oven to 350~. Using a spoon, stir eggs with sugar and vanilla; add butter. Sift Ground Chocolate with flour, baking powder and salt. Stir into egg mixture; add nuts. Spread into greased 8 or 9" square pan. Bake at 350~ for 20-30 minutes. For extra chewy brownies, use 8" pan and less baking time. For cake like brownies use 9" pan and longer baking. Cut into squares.