Preheat oven to 425 degrees.
Remove stems from all of the cherries and remove seeds.
In a large bowl, add cherries, lemon juice, cornstarch, brown sugar, white sugar, vanilla, and cinnamon. Gently toss to combine. Pour cherry mixture into skillet or 2-quart baking dish.
In a medium mixing bowl, combine yellow cake mix, brown sugar, salt, and baking powder. Stir to combine. Add butter, and using a pastry blender or a fork, cut butter into the mixture until it resembles coarse crumbs.
Add crumb topping to cover the cherries entirely. Set in the oven and bake for 25-35 minutes or until crumb topping is a nice golden brown and the juice from the cherries is bubbling.
Serve immediately or let it cool and serve later, it's great either way especially with vanilla ice cream or whipped topping.