Make the gingersnap crust: place a 9-inch fluted tart pan with a removable bottom on a plate or tray and set aside.

In a microwave- Safe measuring cup, add the butter and chocolate. Microwave on high in 15 second intervals until the butter is melted, 45 to 60 seconds. Stir to finish melting chocolate.(it’s okay if the chocolate and butter still look slightly separated.)

In the bowl of a food processor, add the gingersnaps and pulse a few times to break them into small pieces. Add the hazelnuts and process until finely ground, about 30 minutes. Add the crystallized ginger and pulse a few more times to combine. Stream in the butter and chocolate mixture, continuing to pulse until the mixture is well combined. Stop and scrape down the sides of the bowl as necessary.

Transfer the crumb mixture to the tart pan. Use the bottom of a glass to press the mixture into the bottom and sides of the pan. Freeze the crust while you work on the filling.

Make the ganache filling: set a small saucepan with 2- Inches of water over medium heat and bring to a simmer.

In a large heatproof, combine the chocolate, cream, and salt. Set the bowl over the saucepan and stir until the chocolate is melted and combined with the cream, about 10 minutes. Remove from the saucepan. Add the butter and vanilla stir until the mixture is completely smooth and combined. Pour the ganache mixture into the chilled crust and refrigerate at least 4 hours or overnight.

Make the ginger sugar: in a small bowl, rub together the minced ginger and sprinkling sugar with your fingertips until well combined. Sprinkle the ginger sugar around the edge of the tart.

To serve, place the tart pan on top of an elevated flat container(like a large coffee can or soup bowl.) gently press the outer rim of the tart pan down until it slips off the crust. Set the tart, sill on the bottom of the pan, on a plate or platter. With a large offset spatula or long thin knife, slip the blade between the bottom of the crust and the bottom of the tart pan. Run it all rhe around the tart to release and carefully remove the tart pan bottom.

Make sure to keep the tart chilled until ready to serve, slice and serve the tart with the whipped cream, if desired. The tart will keep refrigerated for up to 5 days.