You can substitute sweet onion for fennel and bacon for prosciutto.
Preheat oven to 425°. Remove pizza dough from refrigerator, and let stand 30 minutes or until ready to use.
Meanwhile, trim and discard root end of fennel bulbs. Trim stalks from bulbs, and chop fronds to equal 2 tsp. Thinly slice fennel bulbs lengthwise, and place on an aluminum foil-lined baking sheet. Drizzle with 2 Tbsp. olive oil. Sprinkle with thyme and oregano. Bake at 425° for 35 minutes or until edges are golden brown.
Cook prosciutto in a large nonstick skillet over medium-high heat 1 to 2 minutes on each side or until browned and crisp. Break prosciutto into large pieces.
Turn dough out on a lightly floured surface, and roll into a 17- x 13-inch rectangle (about 1/4 inch thick). Place dough rectangle on a lightly greased (with cooking spray) baking sheet. Brush dough with remaining 1 1/2 tsp. olive oil. Bake at 425° for 15 to 20 minutes or until golden brown. Remove crust from oven, and increase oven temperature to broil.
Top crust with fontina cheese, fennel slices, and prosciutto. Broil 1 minute. Sprinkle with dried crushed red pepper, reserved 2 tsp. chopped fennel fronds, and coarse sea salt. Drizzle with balsamic glaze.
We tested with Acetum Blaze Original Balsamic Glaze.