Adjust rack one-third up from the bottom of the oven and preheat oven to 450 degrees. Butter a 10-1/2 x 15-1/2 x 1-inch jelly-roll pan. Line the bottom and sides with one long piece of wax paper, butter the paper lightly, dust it with flour, and invert over a piece of paper to tap lightly and shake out excess flour.

Place the chocolate and the butter in the top of a small double boiler over hot water on moderate heat. Cover until melted, stirring occasionally with a small wire whisk. Add the powdered dry instant coffee and stir to dissolve. Remove the top of the double boiler and set aside, uncovered, to cool slightly.

Meanwhile, in the small bowl of an electric mixer, add the salt to the eggs and beat until slightly fluffy. Gradually add the sugar and beat at medium-high speed for 15 minutes. Transfer to the large bowl of the mixer.

Stir the vanilla and almond extracts into the chocolate mixture. On lowest speed add the chocolate to the eggs, scraping the bowl with a rubber spatula and beating only enough to blend. Still using lowest speed and the rubber spatula, add the flour, beating only enough to blend. Fold in the nuts, handling the mixture as little as possible.

Turn into the prepared pan and spread very evenly.

Place in the oven and immediately reduce the oven temperature to 400 degrees. Bake 21 to 22 minutes or until a toothpick gently inserted in the middle just barely comes out clean. Do not overbake. These should be slightly moist.

Remove from the oven and immediately cover with a large rack or cookie sheet and invert. Remove the pan and wax paper. Cover with a large rack and invert again. After 10 or 15 minutes cover with a rack or cookie sheet and invert only for a moment to be sure that the Brownies are not sticking to the rack.

Cool completely. The cake will cut more neatly if it is chilled first-it is even best if it is partially frozen. (It may be cut in half and partially frozen one piece at a time if you don't have room in your freezer for the whole thing.)

Transfer to a cutting board. To mark portions evenly, measure with a ruler and mark with toothpicks. Use a long, thin, very sharp knife or one with a finely serrated edge. Use a sawing motion when you cut in order not to squash the cake.

Wrap the Brownies individually in clear cellophane or wax paper (not plastic wrap, which is too hard to handle) or package them any way that is airtight-do not let them stand around and dry out.