Preheat the oven to 350°F (175°C).

In a mixing bowl, combine the pitted cherries, granulated sugar, cornstarch, vanilla extract, and lemon juice. Toss to coat the cherries evenly.

Pour the cherry mixture into a greased baking dish.

In another bowl, mix together the oats, flour, brown sugar, and cinnamon.

Add the melted butter and stir until the mixture is crumbly.

Sprinkle the crisp topping evenly over the cherries in the baking dish.

Bake in the preheated oven for 30-35 minutes, or until the topping is golden brown and the cherries are bubbly.

Remove from the oven and let cool slightly before serving.