For the crust:

1. Food processor: in the bowl of a food processor mix flour with coconut and sugar.
2. Add cold butter and pulse a few times until the butter is the size of peas.
3. Add yolk and pulse just until it starts to come together. Don’t let it become a ball of dough.
4. If the dough is too dry add a tablespoon of water, but only if necessary.
5. By hand: in a large bowl mix flour, coconut, and sugar.
6. Add butter and mix with a dough cutter or with your hands, breaking the butter pieces until they are the size of peas. Be careful not to let the butter start to melt. If that happens, pop the bowl for ten minutes in the fridge before continuing.
7. Add yolk and mix with a fork until it starts to come together.
8. If the dough is too dry add a tablespoon of water, but only if necessary.
9. For both methods: either way, you mix it, turn the dough onto the clean counter.
10. Gather it together and give it some turns until no dry spots are left. It should be soft but don’t overdo it. Just until you have a ball.
11. Wrap in plastic and refrigerate for 1 hour or up to 1 day.
12. You will use an 8-inch tart pan with removable bottom.

Rolling the dough:

1. On a clean counter, roll it to about 1/3 inch thick and a few inches wider than the pan. Add some flour if the dough is too wet to roll, but you probably won't need it.
2. Gently line the pan with the dough, being careful not to stretch it but making sure you cover the whole surface, bottom, and sides.
3. Prick the bottom a few times with a fork and freeze for 30 minutes.
4. Turn the oven to 350ºF /180º C.
5. Cover the frozen dough with a large piece of aluminum foil and add some weight (uncooked rice, beans, flour, pie weights) and bake for 15 minutes.
6. Carefully remove the foil and bake until dry and golden.
7. Let cool completely on a wire rack.

For the lemon cream:

1. Mix sugar, cornstarch, yolks and cream in a glass bowl.
2. Heat in the microwave on high for 30 seconds. Remove and whisk well. Nothing will appear to happen.
3. Repeat another 30 seconds and whisk.
4. Repeat once more if necessary, until you see that it has thickened in some areas.
5. Whisk vigorously until creamy and heat in 10-second spurts until you whisk it and it thickens uniformly.
6. Add the butter and lemon juice and whisk until it is creamy.
7. Be careful not to burn it.
8. Immediately put a piece of plastic wrap or similar touching the whole hot surface. This will prevent it from developing a thick crust.
9. Can be made 2 days ahead and kept in the fridge.

To assemble:

1. Put the baked coconut crust on the serving plate.
2. Add a layer of dulce de leche, spreading carefully.
3. Add the lemon cream on top at the last minute.
4. Drizzle with some heated dulce de leche or decorate with toasted coconut flakes.