Dissolve yeast in warm water in a large bowl; let stand 5 minutes. Stir in yogurt. Lightly spoon flours into dry measuring cups; level with a knife. Add 1/2 cup bread flour and whole wheat flour to yeast mixture; stir with a whisk until smooth. Cover and let rise in a warm place (85°), free from drafts, 2 hours (batter will be bubbly, lacy, and weblike).
Stir in salt and oil. Add 1 1/2 cups bread flour (1/2 cup at a time); stir with a wooden spoon (dough will become very difficult to stir).
Turn dough out onto a lightly floured surface. Knead until smooth and elastic (about 10 minutes); add enough of remaining bread flour, 1 tablespoon at a time, to prevent dough from sticking to hands (dough will feel tacky). Place dough in a large bowl coated with cooking spray, turning to coat top. Cover and let rise in a warm place (85°), free from drafts, 2 hours or until doubled in size. (Press 2 fingers into dough. If indentation remains, the dough has risen enough.)
Place pizza stone on the bottom rack in oven. Preheat oven to 500°.
Punch dough down; turn out onto a lightly floured surface. Cover and let rest 5 minutes.
Divide dough into 8 equal portions. Working with 1 portion at a time, (cover remaining dough to keep from drying), stretch each portion into a 6-inch oval. Cover and let rest 5 minutes.
Make indentations in top of dough portions using the handle of a wooden spoon or your fingertips; cover and let rise 20 minutes.
Place 2 dough portions on the back of a pizza peel dusted with 1 tablespoon cornmeal. Slide onto preheated pizza stone or baking sheet lined with parchment. Bake at 500° for 6 minutes or until lightly browned. Repeat with remaining dough and cornmeal. Serve immediately.