Chocolate Peppermint Raspberry Tart

Preheat the oven to 350 F. In a medium bowl combine the cracker crumbs with the melted butter, sugar and the salt. Press into the bottom of a 4x14" tart tin. Press the mixture up the sides and firmly along the bottom. Bake until firm, 15-20 minutes. Set aside to cool.
In a medium saucepan combine the heavy cream, 6 of the peppermint sprigs, the sugar and the salt. Simmer over low heat for 5 minutes, stirring frequently to avoid scorching. Then remove from heat, set aside and allow to come to room temperature.
Meanwhile, melt the chocolate. You can do this in a saucepan on very low heat, in the top of a double boiler or in the microwave for 30 second increments. Using a pastry brush or the back of a spoon, spread the chocolate along the bottom and halfway up the sides of the cooled tart shell. Refrigerate until firm.
In a small bowl, combine the water and gelatin, and allow to sit 5-10 until completely softened.
Once the cream and mint mixture has cooled, remove the mint by pouring the mixture into a bowl through a sieve. Then return the mixture to the saucepan on a low heat. Add the gelatin mixture and the yogurt and stir until thoroughly combined. Carefully pour the mixture into the tart shell and transfer it to the refrigerator. Chill for 5-6 hours.
Prior to serving garnish with berries and the extra sprigs of mint.