In a large bowl, dissolve yeast in 45 mL (3 tablespoons) of warm water then add the sugar. Mix and set aside for about 10 minutes.
When the yeast mixture begins to foam, add the salt.
Using a stand mixer, combine the flour, warm water and yeast mixture until it forms a large ball of dough.
Remove the dough from the stand mixer and on a floured surface, knead by hand for 5 minutes.
Place the dough in a greased bowl and cover with a clean dish towel Turn on the oven light and place the bowl of dough in the oven. The heat generated by the light bulb will be warm enough to help the dough to rise. Let it rise for 30 minutes.
Remove the dough from the oven, and set it to 400ºF.
Roll out the dough to obtain an 11 in x 9 in rectangle.
Sprinkle the grated parmesan over the dough, add the apples and drizzle with oil. Top with red onions and prosciutto. Season with a generous amount of pepper.
Bake in the oven for 20 minutes or until the dough and the toppings are golden brown.
Garnish with fresh thyme before serving.