Preheat oven to 400 degrees.
In a medium bowl, toss garbanzo beans with olive oil, cumin, ½ teaspoon salt, pepper, and cayenne pepper.
Transfer mixture to rimmed baking pan. Bake until garbanzos are golden and crisp, stirring occasionally with a spatula, about 25-30 minutes.
Remove the garbanzos from oven and stir in pistachios. Bake until beans and pistachios are crunchy, about 15-20 minutes. Sprinkle with remaining ¼ teaspoon of salt.
Place in a serving bowl and serve warm or room temperature. Store any leftovers in an airtight container.