For the hummus, place the drained garbanzos, lemon juice, garlic, cumin, and olive oil in a food processor. Process until blended, about 1 minute. Refrigerate overnight. Bring to room temperature before making the bruschetta.
Spread a teaspoon of butter on each slice of ciabatta; sprinkle with a teaspoon of Parmesan cheese.
Place under broiler until slices are golden, about 3 minutes.
Remove from oven and spread with a generous tablespoon of hummus.
Sprinkle with a dusting of paprika.
To serve, top with tomato slices, feta cheese, and a sprinkle of the oregano and garlic powder.