Dissolve yeast and sugar in warm water. Add 2 cups flour and beat well. Add salt and remainder of flour, adding just enough flour to make a workable dough.
On a lightly floured surface, knead dough until smooth and elastic, about 10 minutes. Place dough in a well-greased bowl, turning to coat, cover with a damp towel or plastic wrap, and let rise until doubled in bulk, 1 to 2 hours.
Punch dough down, transfer to lightly floured surface, and divide into pieces. Dividing dough into 12 pieces will result in 4- to 5-inch rounds; six pieces will make 7-inch rounds; three pieces will make 10-inch rounds, and dividing dough in half will mak
Set baking sheets in a warm place and let rounds rise till very puffy, about 1 hour. After the first half hour, gently press down the middle of the rounds; you want the middle to remain fairly flat, while the edges rise.
When rounds are well-risen, brush lightly with olive oil and sprinkle with cheese(s) of your choice (for savory pizzas), or brush lightly with butter and sprinkle with cinnamon sugar and nuts. Place baking sheets in a preheated 500°F oven for 10 minutes,