Make the ganache: Place the cream in a heavy-bottomed saucepan over medium heat and bring to a boil. Pour the hot cream over the chopped chocolate and use a whisk to mix. The hot cream will melt the chocolate. Continue to whisk until the ganache is smooth. Set aside and allow them to cool.
Place the butter, salt, sugar, egg and almond flour in a medium-size mixing bowl. The almond flour will add flavor to the dough. Use an electric mixer set on medium speed to beat the mixture just until combined.
Add the cake flour and cocoa powder and mix just until the dough is smooth and holds together, about 30 seconds. Remove the dough from the bowl and pat into a disk. Wrap the dough in plastic wrap and place in the refrigerator for at least 1 hour before using.
When you are ready to use the dough, remove it from the refrigerator and give it 4 or 5 quick raps with a rolling pin. This softens the cold butter. Roll the dough to the desired size on a lightly floured work surface.
Use a 2-inch plain cutter to cut the tart shells from the dough. Use a 11/2-inch fluted cutter to cut the "gears" for the top of each tart. Place each tart shell in a flexible mini-pan and use a fork to dock the dough. Place the gear pieces on a parchment paper lined baking sheet. Bake each pan of dough for 10 minutes.
Assemble the tarts: Place the ganache in a piping bag (no tip). The ganache should be slightly softer than the consistency of toothpaste. Pipe ganache into each tart. Set a gear shaped piece on end and tarts are ready to serve.