In a large bowl combine flour, sugar, baking powder, and salt. Stir to combine. Add oil, eggs, milk, liqueur, and vanilla extract, and mix to form a batter.
Lightly coat the inside of the waffle maker with nonstick cooking spray or wipe with an oiled paper towel. Pour approximately a quarter cup of batter into waffle maker and close. The waffle maker should signal when waffles are ready. Waffles should be lightly browned.
In a double boiler over low heat, combine non-dairy whipped topping and chocolate. Stir constantly until chocolate is melted and mixture is uniform. Pour over waffles.