Put the garlic, 2 tablespoons of the oil, 2 teaspoons of the pimentón, and the salt, black pepper, and cayenne in a large bowl, food processor, or blender. Mash or process until relatively smooth.
Add the chickpeas, tahini, and lemon juice, and mash or process until the hummus is uniform in texture and as smooth as you like it, adding the reserved garbanzo cooking liquid or water as needed if the mixture is too thick. Taste and adjust the seasoning. Sprinkle the remaining ½ teaspoon pimentón over the hummus, drizzle with the remaining 1 tablespoon oil, and serve immediately (or cover and refrigerate for up to a week).