Mix water, cornstarch, and balsamic vinegar together in a small bowl (and food coloring if using). Place in a medium saucepan with half of the strawberries and all of the white sugar over medium high heat and stir to combine.

Bring to a boil, stirring constantly. Reduce heat to medium-low and simmer until thickened enough that liquid doesn't drip off spoon, again stirring constantly.

Turn off heat and stir in remaining strawberries. Transfer to a small bowl, cover with plastic wrap, and place in fridge until chilled completely.

15 minutes before assembly pull out pie crust to come to room temperature. While pie crust sits stir together flour, brown sugar, oats, and cinnamon in a small bowl. Use your fingers to mash in the butter until mixture resembles coarse crumbs.

Preheat oven to 400°F. Line a baking sheet with parchment paper. Carefully unroll pie crust in center of parchment. Pour filling into the center of pie crust leaving a 2" perimeter all the way around. Fold pie crust over the edges off filling. Sprinkle crumble topping over entire top.

Stick in oven and bake until top is golden and crisp. About 20-25 minutes. Remove from oven. Let cool at least 15 minutes. Slice, serve, enjoy!