Preheat the oven to 375°F (190°C).
Wash and dry the pears. Cut them in half lengthwise and use a teaspoon or melon baller to remove the cores and seeds.
Arrange the pear halves cut side up in a baking dish.
Drizzle the pears with 1 tablespoon of honey. Sprinkle with cinnamon, if using.
Pour 2 tablespoons of water into the bottom of the baking dish.
Bake for 25–35 minutes, until the pears are tender when pierced with a knife but still hold their shape.
Remove the pears from the oven and let them cool for 3–5 minutes.
Place one small scoop of vanilla ice cream on each pear half.
Drizzle with the remaining honey or syrup from the baking dish and sprinkle with chopped pistachios. Serve immediately.