Preheat oven to 350°F (180°C). Place wafers in a food processor fitted with the knife attachment, and pulse on and off until crumbs form. Do not overprocess or mixture will become clumpy and hard to spread.

Pat into a nine by 13-inch (20×30-centimeter) baking pan lined with Gefen Parchment Paper to form a thin crust. You can wet your hands slightly to make it easier to spread. Bake for 10 minutes. Remove from oven and allow to cool, but leave oven on.

Meanwhile, over low-medium heat, heat the parve whipping cream and the chocolate until melted and a pudding-like texture is achieved. Whisk together occasionally, so mixture is smooth and creamy. Cool for five minutes (not much longer or it’ll solidify somewhat).

Beat eggs until lemony, about one to two minutes, adding the sugar and salt gradually. Fold chocolate mixture into beaten eggs. Add hazelnut extract. Mix gently until fully incorporated. Pour evenly onto crust and bake for 35 minutes or until top springs back when touched. Cool.

Melt baking chocolate and oil together. Pour on top of the filling, smoothing out with a spatula. If adding garnish, do so now before glaze hardens. Refrigerate and cut into squares when cool. Use a sharp, straight-edged knife, dipped into warm water, to cut.