In a saucepan, caramelize the sugar mixture until amber using the dry method.
Remove from the heat and add the glucose syrup to the caramelized sugar.
Bring the cream to a boil. With the caramelized sugar mixture at low heat, stream in the hot cream, making certain that the caramelized sugar mixture is entirely incorporated.
Add the pumpkin purée and 1 tsp of the gingerbread spice mix.
Return the cream mixture to a boil.
Pour the hot cream mixture over the chopped milk chocolate and let sit for 1 minute to allow the chocolate to melt.
Using a paddle, stir the mixture in vigorous small circles in the center of the bowl until it emulsifies.
Stir outward in larger circles to spread the emulsion throughout the bowl, checking to see that all of the chocolate has melted. If necessary, heat the ganache over a hot water bath to melt the chocolate. The temperature of the ganache should not exceed 32°C/90°F.
Stream in the brandy, stirring until the mixture is homogeneous.
Pour the ganache into a hotel pan, allowing the ganache to cover the bottom of the pan in a thin layer. Place plastic wrap directly on the surface of the ganache.
Allow to rest at room temperature until the ganache reaches 32°C/90°F or slightly lower. The cooled ganache should be of a thick but fluid consistency to properly fill the shells.
Using a disposable pastry bag with a small opening cut in the tip, fill the lined molds with the ganache to within 3 mm/⅛ in of the tops.
Allow the ganache to crystallize at room temperature until the top is solid, for several hours or overnight.
Seal the truffles using the tempered dark chocolate.
Allow the tops to crystallize at room temperature. Then refrigerate the filled molds until the chocolate pulls away from the inside of the molds, approximately 20 minutes.
Place a piece of stiff cardboard over each mold and invert the mold to release the finished confections.