Line a standard size muffin pan with 8 foil liners.
Graham Cracker Crust
Stir together crushed Graham crackers, sugar and butter until well combined.
Press mixture evenly onto the bottom and sides of lined muffin pan cups. Bake in a 350˚F (180˚C) oven for 8 minutes. In the mean time, work on the custard. When crust is ready, remove and cool on a rack. Leave oven on.
In a small bowl, whisk egg yolks lightly. Set aside.
Heat butter in a pan and cook flour. Pour in mango puree, coconut milk, and sugar stirring over medium heat until thick and bubbly. Remove from heat. Stir in egg yolks until well combined.
Putting it together
Pour warm filling into baked tart shells.
Bake in a 350˚F (180˚C) oven for 12 minutes. Remove and cool on a wire rack.
When it is cool enough to handle, transfer baked tarts to a flat pan. Cover with foil and chill for at least 4 hours in the fridge.