Adjust a rack to the lowest position in the oven and preheat oven to 350°. Butter an 8'' x 3'' one-piece cheesecake pan all the way up to the rim and including the inside of the rim itself. You will also need a larger pan (for hot water) to place the cake pan in while baking: The larger pan must not be deeper than the cheesecake pan. Set aside.
In the top of a small double boiler over hot water on low heat, melt the chocolate and set it aside.
In the large bowl of an electric mixer, beat the cheese until it is completely smooth. During the beating, frequently scrape the sides and bottom of the bowl with a rubber spatula. When the cheese is smooth, beat in the vanilla and almond extracts and the sugar. Beat well and then add the eggs one at a time. After adding the eggs, do not beat any more than necessary to mix.
Remove the bowl from the mixer. Place one-third of the batter (2 cups) in the small bowl of the electric mixer. Add the melted chocolate and beat until smooth.
Spray the buttered cake pan with nonstick spray, then pour in the light-colored mixture.
Fit a large (about 16'') pastry bag with a plain #6 ( ½'') tube. Fold down a deep cuff on the outside of the bag and twist the tube end of the bag to prevent the mixture from running out.
Place the chocolate mixture in the bag.
Now, work at table height, not counter height (you will have better control at table height). Place the cake pan on the table. Unfold the cuff on the pastry bag. Untwist the tube end of the bag. Place the tip of the tube in the center of the top of the cake, inserting it ¼'' to ½'' into the cake. Squeeze out enough of the chocolate mixture to form a perfectly round ball about 2'' wide. There will now be a dark polka dot in the center of the cake.
Then, using the same procedure, squeeze out 6 smaller balls around the rim. In order to space the 6 balls evenly, place the first one at twelve o'clock (straight up), the next at six o'clock (straight down). Then, two on each side. Doing it this way, the chances are that the spacing will be quite even. The balls around the rim should be smaller than the one in the center, and they should not touch each other or the center ball. If you have some chocolate mixture left over, add it to the center ball; if you still have some left over, add a bit to each of the other balls.
The top of the cake will not be smooth and level now, but it will level itself during baking. When baked, the polka dot in the center will be about 2½'' wide, the dots around the rim will be about 1½'' wide.
Place the cake pan into the larger pan. Place it in the oven and pour hot water into the larger pan, about 1½'' deep.
Bake for 1½ hours. The top of the cake will become golden-brown and it will feel dry to the touch. But the cake will still be soft inside (it will become firm when it has cooled and been refrigerated).
Lift the cake pan out of the water and place it on a cake rack. Cool the cake in the pan for 2½ hours. (Do not cool it in the refrigerator or the butter will harden and the cake will stick to the pan.)
Cover the pan with plastic wrap. Place a flat plate or small board upside down over the pan and turn the pan and the plate or board upside down. Carefully remove the pan.
Carefully and evenly sprinkle the graham cracker crumbs over the bottom of the cake. Gently place another flat plate or small board upside down over the cake and carefully invert again (without squashing the cake), leaving the cake right side up. Remove the plastic wrap.
Refrigerate for several hours or overnight.
To serve, dip a sharp knife in very hot water before making each cut (shake off the water but do not dry the blade). Make the first cut through the middle of one of smaller dots and the second cut (the one that will release the first portion) between two of the smaller dots.