Put the cookies crumbs into a mixing bowl and add the melted butter, mix thoroughly.
Once the crust ingredients are mixed press them into the tart pan.
Up to 3 hours before serving, one can finish making the tart. Cream together the creme fraiche and the brown sugar until the sugar has dissolved and the creme is a consistent color.
Spoon all of the creme onto the crust and smooth it with a spatula.
Allow about a 1 inch margin of crust around the perimeter of the tart.
The tart can be loosely covered with plastic wrap and kept in the refrigerator for up to 3 hours before serving.