Mix 1 cup flour, sugar, and yeast in bowl. Stir in the water and oil until blended. Pulse 1 3/4 cups flour and salt in food processor to mix. Add yeast mixture and pulse until blended. With motor running, add remaining flour, 1 tablespoon at a time, until soft dough forms (you will need to process about 2 minutes). Dough is ready when it comes together in a ball.
Dust work surface lightly with flour. Turn out dough and knead until smooth, 1 to 2 minutes. Roll dough into 1 1/2-inch balls in your hands. Then flatten into 3-inch rounds. Cover with clean kitchen towel; let rest 10 minutes.
Preheat oven to 450°F. Line two baking sheets with parchment paper.
Divide dough into 4 pieces. Wrap 3 in plastic; refrigerate. Cut remaining dough into 12 equal pieces; shape each into 1 1/2-inch ball. Arrange on baking sheets; flatten into 3-inch rounds. Lightly coat with nonstick cooking spray.
Cut tomatoes into thin slices, then fan out slices. Top each pizza with 2 or 3 slices. Sprinkle with 1 teaspoon fontina, a little Parmesan, plus a few olive slivers and oregano leaves.
Bake until bubbly and crust is golden, about 10 minutes. Repeat with remaining dough.