Preheat oven to 350°F. Toast pistachios on a rimmed baking sheet, tossing once, until golden brown, 5–7 minutes. Let cool, then coarsely chop.
Mix cinnamon and cardamom in a small bowl.
Divide ice cream among 4 small serving bowls or coffee cups. Sprinkle spice mixture over and pour 2 Tbsp. espresso into each bowl. Top with pistachios.
