2 1/4 cups unsalted margarine
Melt margarine and pour into bowl. Mix margarine with granulated sugar until blended (either by hand or with mixer). Add vanilla and gradually add eggs, mixing well after each egg. Sift the dry ingredients together, add egg mixture, blending until combined (do not overmix). Divide batter into two 9x9 greased and floured parchment-paper-lined pans. Bake at 350 Fahrenheit for 30-40 minutes, test middle of brownie with toothpick. Cool completely before removing from pan or cutting.
2 1/2 pounds bittersweet chocolate
Melt chocolate and butter in mixing bowl over hot water. Add egg yolks and water, using mixer to blend. In a large bowl, combine chocolate mixture and whipped cream, fold until smooth. Whisk egg whites until stiff then add granulated sugar (meringue), whisk mixture for another 30 seconds. Fold meringue into the chocolate mixture until smooth. Refrigerate mousse for 24 hours before using. Spoon the mousse into a champagne or martini glass and serve with a simple sugar cookie.