Preheat the oven to 450°F and grease a large pizza pan.
To make the crumb topping, mix the flour, sugar, brown sugar, and salt. Add the butter and use a pastry blender or fork to combine until the mixture resembles cornmeal.
To make the pizza, spread the dough on the prepared pizza pan and prick with a fork 8 to 10 times. Place in the preheated oven for 5 minutes. Remove from the oven, spread the cherry pie filling over the crust, and sprinkle with 1/4 cup of crumb topping. Return to the oven and bake for 20 to 25 minutes.
While the pizza is cooking, make the sweet drizzle by combining the powdered sugar, vanilla extract, and 1 1/2 tablespoons of milk. Mix well. You may need to add an additional tiny splash of milk so the consistency is runny enough to drizzle.
When the crust is golden brown, remove the pizza from the oven and top with the sweet drizzle.