For the tart shell

1. Finely grind the coconut in a food processor; set aside.
2. Beat butter in the bowl of an electric mixer fitted with the flat beater until smooth and creamy. Add powdered sugar and beat again until well combined, occasionally scraping the bowl and paddle.
3. Add coconut, egg, vanilla and salt. Mix to combine.
4. Add flour and then mix at low speed until dough forms. Do not over mix.
5. Pat the dough into a ball and flatten into a disk. Wrap dough in plastic and refrigerate for at least 45 minutes or overnight for easier handling.
6. When ready to bake the shell, preheat oven to 375 degrees.
7. Remove half of the chilled dough from the refrigerator, storing any leftover in a plastic bag in the freezer for another use. It will keep up to 4 weeks.
8. On a lightly floured surface, roll the dough into a round disc slightly larger than the tart pan and about 1/8 inch thick. Rotate dough frequently to prevent it from sticking to the surface. Using both hands or the rolling pin, transfer the dough to the tart pan. Ease the dough into the pan, pressing the dough well into the corners and crevices. Prick bottom of shell with a fork.
9. Bake shell until golden brown, 12 to 14 minutes. Let cool completely in the pan on a wire rack.

For the lemon curd

1. In a medium saucepan over medium-high heat, whisk lemon juice and lemon zest with 6 tablespoons of the sugar. Bring to a boil and set aside.
2. In a large mixing bowl, whisk eggs and remaining sugar thoroughly to create a smooth mass.
3. Slowly add about one-quarter of the boiled lemon juice mixture to the eggs while continuing to whisk vigorously. This will slowly warm up (or temper) the eggs so lumps won’t form.
4. Pour egg-lemon mixture into the saucepan containing the remainder of the lemon juice mixture. Return to the stove and whisk vigorously, bringing mixture to a boil for 1 minute. Continue to simmer the mixture until the lemon curd is the consistency of hollandaise sauce. Remove the saucepan from the heat and place in an ice bath to cool the lemon curd to 120 degrees (or warm but not hot to the touch), about 3 minutes.
5. Remove from ice bath and add butter in 5 increments, stirring gently with a rubber spatula until smooth.
6. Pour lemon curd into the baked tart shell and chill in the refrigerator for several hours or overnight.

For serving

1. Beat the cream with the sugar until stiff peaks form. Transfer whipped cream to a pastry bag fitted with a star tip and pipe cream around the tart.