Defrost dough according to package directions. Brush pan with 1 teaspoon of the oil. Stretch and pat dough into pan; fold edges over slightly to form crust. Cover with plastic wrap and allow to rest for 20-30 minutes or until slightly risen.
Over medium high heat, heat remaining oil in medium skillet until hot. Add sliced mushrooms; cook, stirring occasionally, until golden brown. Season to taste with salt and pepper.
Preheat oven to 375ºF.
Sprinkle dough with 1-1/2 cups cheese. Top with mushrooms and small mounds of spinach. Sprinkle with remaining cheese. Combine diced tomatoes with pizza sauce; spoon sauce mixture randomly over top of pizza; do not spread.
Bake 18-20 minutes or until crust is golden brown and cheese is melted. To serve, cut in to wedges.