Mix all dry ingredients together.
Melt butter and cool slightly.
Mix egg with melted butter and pour immediately into dry ingredients,
Form into a dough ball, place between two sheets of parchment paper. Roll out to the shape of your pan. Refrigerate for ten minutes.
The tart dough will probably have to be put into the tart pan in pieces, but that okay.
Once tart dough is secured in pan, pre-bake, place in freezer for 10 minutes. In meantime, gather ingredients for chocolate filling.
Bake at 350 (180 C) for 8-10 minutes.