Preheat the oven to 350°F (175°C).

In a food processor, pulse graham crackers until fine crumbs. Blend in melted butter and sugar to combine.

Transfer the mixture to a pie pan, pressing firmly to create an even crust. Refrigerate for 10-15 minutes.

In a clean food processor, combine diced mango, sweetened condensed milk, eggs, lemon zest, and vanilla. Blend until smooth.

Pour the custard into the chilled crust, filling to about ¼ inch from the top.

Bake for 35-40 minutes until edges puffed and center slightly jiggles.

Cool at room temperature for 30 minutes, then refrigerate for at least 4 hours.

Serve cold, optionally garnished with whipped cream or fresh mango slices.