Put the sugar, vanilla, salt and milk in your blender and blend until the sugar is dissolved. Add the ricotta and puree until smooth.
Pour the ricotta mixture into a bowl and stir in the chopped pistachios & dark chocolate.
Spray a small bowl or tray that fits your cracker size/shape, and set a cracker on the bottom. (I used two small square bowls that each fit half a cracker nicely.) Spread a layer of the ricotta mixture on top, then add another cracker, then another layer of ricotta. Repeat until the ricotta mixture is gone, ending with the ricotta mixture on top. Cover your bowl (or tray or whatever you’re using) with a plate that fits tightly (or if you must, use plastic wrap) and refrigerate overnight.
To serve, cut wedges of the “cake” and use a spatula to place them on your plate, drizzle with chocolate syrup and serve.