Preheat your Blackstone Pizza Oven to 450°F-500°F.
In a medium bowl, mix the peaches, water, cornstarch, sugar, melted butter, cinnamon, and lemon juice. Pour the mixture into an oven-safe pan.
In a small bowl, mix the all-purpose flour, brown sugar, grated butter, and cinnamon with a fork until crumbly. Spread the crumble mixture evenly over the peach filling.
Place the peach crumble into the preheated pizza oven and bake for 15 minutes. If needed, turn off the pizza oven after 8-10 minutes to prevent the top from burning. The residual heat will finish cooking the crumble.
Remove from the oven and let it cool slightly. Serve with a side of vanilla ice cream.
