Preparation Position rack in center of oven and preheat to 375°F. Horizontally, cut off top 1/3 of bread and reserve for another use. Scoop or cut out interior of bread, leaving 1/2-inch shell. Place shell on large baking sheet. Fry sausage in heavy medium skillet over medium-high heat until cooked through, breaking up with fork, about 10 minutes. Drain all fat from skillet. Combine spinach and 1/2 cup pesto in small bowl. Sprinkle half of cheese over bottom of bread shell. Spread spinach mixture over cheese. Arrange sausage evenly over spinach layer. Spread eggplant appetizer over. Bake pizza until filling is heated through, about 20 minutes. Combine marinara sauce with remaining cheese and spread over top of pizza. Dot with remaining 2 tablespoons pesto. Bake until cheese melts and topping bubbles, about 12 minutes.
Preparation Position rack in center of oven and preheat to 375°F. Horizontally, cut off top 1/3 of bread and reserve for another use. Scoop or cut out interior of bread, leaving 1/2-inch shell. Place shell on large baking sheet. Fry sausage in heavy medium skillet over medium-high heat until cooked through, breaking up with fork, about 10 minutes. Drain all fat from skillet. Combine spinach and 1/2 cup pesto in small bowl. Sprinkle half of cheese over bottom of bread shell. Spread spinach mixture over cheese. Arrange sausage evenly over spinach layer. Spread eggplant appetizer over. Bake pizza until filling is heated through, about 20 minutes. Combine marinara sauce with remaining cheese and spread over top of pizza. Dot with remaining 2 tablespoons pesto. Bake until cheese melts and topping bubbles, about 12 minutes.