Make the sauce: Heat olive oil in a saucepan over medium heat. Add garlic and sauté 1–2 minutes until fragrant. Stir in tomatoes, vinegar, oregano, salt, and pepper. Simmer 10 minutes, then mash or blend until smooth. Cool slightly before using.
Prepare tortilla bases: Preheat oven to 400°F (200°C). Brush tortillas lightly with olive oil on both sides. Cut out 2–3 circles from each tortilla using a cookie cutter or glass (about 4 inches wide). Place on a baking sheet.
Decorate your pizzas: Spread a thin layer of sauce on each tortilla circle. Add shredded mozzarella. Cut ghost shapes from mozzarella slices and pumpkin shapes from cheddar. Place on pizzas. Slice olives in half and cut slivers for “spider legs.” Arrange into spider shapes on pizzas.
Bake: Bake for 8–12 minutes, or until tortillas are crisp and cheese is melted.
Serve: Let cool slightly, then serve warm and spooky!