Preheat the oven to 450°F (232°C) with a pizza stone on a lower rack.
Brush two tortillas with 1 tsp olive oil each. Bake separately for 3–5 minutes each, until crisp and lightly browned.
Brown the ground beef until fully cooked. Stir in taco seasoning without water. Warm the refried beans and enchilada sauce separately.
Spread beans over the two remaining tortillas. Add beef and cheddar. Bake each for 3–5 minutes, until the cheese melts and the edges brown.
Add lettuce to each baked bottom layer. Brush the crisp tortillas with warm enchilada sauce and stack them on top.
Thin the sour cream, pipe a spiderweb over each pizza, add the plastic spiders for decoration, remove them before eating, slice, and serve immediately.