Cut the Turkish delight into thin slices. In a bowl mix together the flour, cornmeal and sugar.
Separately, extinguish the baking soda in the vinegar and mix these with the water, oil and vanilla. Add the liquid ingredients to the dry ones and stir very well.
Oil and flour an 8″ (20 cm) square form and pour the mixture in it. Arrange the slices of Turkish delight on top and sprinkle with walnuts if desired.
Bake in a preheated 356°F (180 °C) oven until ready.