Preheat the oven to 375 degrees F.
Cut a handful or two of the cherries in half, so you have some whole and some half. Place them in a 9-inch round baking dish.
Whisk together the sugar and cornstarch, then sprinkle it over the cherries and toss well. Add in the vanilla extract and toss. Let sit for 15 minutes. Toss again. Place the butter pieces on top of the cherries.
In a large bowl, whisk together the oats, sugar, flour, cinnamon and salt.
Use a fork to add the softened butter and then use your hands to bring the mixture together, moistening all of the mixture until it resembles sand. Sprinkle it evenly over the cherries.
Bake for 40-45 minutes, until the crisp on top is golden and the cherries underneath are bubbling.
Serve warm with vanilla ice cream!