Dissolve the yeast in the lukewarm water and leave aside in a warm spot until foamy. In the bowl of a mixer, sift the flour and add the yeast mixture. Add the rest of the water little by little, working the dough well after each addition.
Preheat oven to 180° C
Dust your bench with flour and lay the dough out, knead for about 5-10 minutes or until the dough is elastic and bounces back when you poke it. Form into a ball and place it back into the bowl and cover with a damp cloth and left aside in a warm spot until it doubles in size, roughly one hour.
Grease a rectangular baking pan with some olive oil before dividing the dough into two balls, one slightly larger than the other. Roll out the larger ball on your floured bench roughly to the size of your pan, about 3 cm thick.
Lay the dough in the pan. Scatter two thirds of the Midnight Beauty grapes on the first dough layer and sprinkle half of the sugar, and a drizzle of olive oil. Roll out the second ball of dough to the size of the pan and cover the grapes with this second layer of dough and top with the remaining grapes, sugar, and olive oil.
Bake for about 25-30 minutes or until the lightly golden. Allow to cool and then dust with the icing sugars. Enjoy as is, or with a little more olive oil on the side.