Spooky 7 Layer Halloween Spiderweb Taco Dip

Name: Spooky 7 Layer Halloween Spiderweb Taco Dip
Prep time: 30 min
Total time: 30 min
Cuisine: American, Mexican
Ingredients: 1 large garlic clove (minced); salt and pepper (to taste); 2 avocados (peeled and pit removed); ¼ cup onion (finely diced); 1 jalapeño (seeds removed, finely diced); 2 to 3 tablespoons freshly chopped cilantro; ¼ teaspoon cumin; ¼ teaspoon chili powder; 1 lime (juiced); 1 cup sour cream; ¾ teaspoon chili powder; ½ teaspoon cumin; pinch of salt; 1 can refried beans (16 ounces) (vegetarian or fat free); 1 cup fresh salsa (SEE NOTES); 1 ½ cups finely shredded Mexican cheese; 1 small tomato (diced); 1 scallion (sliced thin); 3 tablespoons sour cream; 3 pitted large black olives (plus more for garnish (optional))