Whisk together the brown sugar, graham cracker crumbs, and salt in a medium sized bowl. Add the melted butter and stir until well combined. Press the crumbs into the bottom and sides of a 9-10” tart pan with a removable bottom. Place in the fridge to chill while you prepare the filling.
In a large bowl, beat the mascarpone cheese on medium speed until creamed and no lumps remain, about 1 minute. Be sure the cheese has come to room temperature or you will have a clumpy filling. Add the brown sugar and beat to combine, about 30 seconds. Add in the honey slowly with the mixer on low. Scrape the sides of the bowl and beat for an additional 30 seconds to ensure everything is well combined.
In a separate bowl, beat 1 cup of the heavy cream on medium low speed until it gets frothy. Increase the speed and beat until stiff peaks form. Do not overbeat.
Fold about half of the whipped cream into the mascarpone mixture. Add the remaining half and fold to combine. If you notice your filling is a bit clumpy, add in the additional 1/3 cup of cream and beat briefly to smooth out.
Spread the filling into the prepared tart crust and allow to chill in the fridge for several hours to firm up. Once ready to serve, garnish the tart or each slice with figs, pistachios, and an extra drizzle of honey, if desired. Store in the fridge up to 3 days.