Peel and dice mangoes into bite-sized cubes. Place in a mixing bowl.

Add granulated sugar, lemon zest, and lemon juice. Mix well and set aside.

In a food processor, combine flour, diced cold butter, granulated sugar, vanilla extract, and sea salt. Pulse several times until crumbly.

Add water and pulse again until the dough holds together when pinched but still feels crumbly.

Preheat oven to 350°F (175°C).

Spread half of the crumble dough evenly into the bottom of a 7.5×9.5×2-inch glass baking dish. Press gently to form a base.

Pour the mango filling over the base and spread evenly.

Sprinkle the remaining crumble dough over the mango filling to cover completely.

Bake for 45–50 minutes, until the topping is golden brown and the mango filling bubbles at the edges.

Remove from the oven and let cool at room temperature.

Serve warm with vanilla ice cream if desired.