Pan of boiling water and Flat pan for water bath Adjust rack 1/3 up from bottom of oven/preheat to 350. Line a 6 cup capacity loaf pan with foil, wrinkling as little as possible. Brush foil with melted butter or, just before pouring batter in, spray with Pam. Resift cornstarch 3 times and set aside. Chop chocolate and place in heavy pan. Dissolve coffee in boiling water and pour over chocolate, cover and place over low heat to melt. Stir with whisk, transfer to small bowl and set aside to cool slightly. In bowl of large mixer, beat butter till soft, gradually add sugar and beat for 2 to 3 minutes, scraping bowl. Add egg yolks, one at at time, beating well. Continue to beat till mixture is pale and creamy. Add choc. at low speed, then add cornstarch and beat only till smooth, scraping bowl as needed. In another bowl, beat whites with salt only till whites just stand up; do not overbeat. Add rounded TBLS. of whites to chocolate mixture and stir to mix. Repeat a few times to lighten mix, then stir in the remaining whites, half at a time, folding gently but completely. If using Pam, spray now/pour batter into pan. Lift pan in both hands and move it gently back and forth to even out batter. Place in larger pan (which may not be deeper than cake pan) and pour boiling water in, about an inch deep. Bake for 50 to 55 minutes until a tester gently inserted into the middle, all the way to the bottom, comes out just barely clean and dry. Test several times to be sure. There will be a thin crust on top; the middle will be soft. Do NOT overbake. Turn off heat; open oven door a few inches and let cake stay in for 20 minutes. Open door all the way and let cake stand in oven for another hour till room temp. Remove cake from water bath and dry cake pan. Invert onto serving plate and remove foil. Serve upside down or freeze. Can be covered with chocolate curls sprinkled with powdered sugar or with whipped cream and berries. ----