Step 1

Preheat oven to 350°F.

Step 2

Place tortillas on a large baking sheet, and bake for 10 minutes, or until crispy. Let cool.

Step 3

Meanwhile, mix together crabmeat, lime zest and juice, mayonnaise, paprika, garlic powder, chopped cilantro, chili flakes, and a pinch of salt in a large bowl until combined. Refrigerate until ready to build the tostada.

Step 4

Place black beans, chili powder, 2 tablespoons water, and a pinch of salt in a blender. Blend until it reaches a smooth, saucelike consistency.

Step 5

Mash avocado with cumin and 1/8 teaspoon salt in a medium bowl.