a 10-inch nonstick tart pan with removable bottom; pie weights; a piping bag fitted with a plain tip
For the coconut-almond crust: Preheat the oven to 350 degrees F. Place the coconut on a baking sheet and toast in the oven until golden brown, about 3 minutes. Let cool. Set aside 2 tablespoons of the coconut for garnishing the tart.
Combine the remaining 2 tablespoons cooled toasted coconut, the all-purpose flour, almond flour and salt in a medium bowl; set aside. In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter and sugar until light and fluffy, about 2 minutes. Add the almond extract and egg and beat until combined, scraping down the sides of the bowl as needed. Add the flour mixture and beat on low speed until all of the dry ingredients are just incorporated, about 30 seconds. Form the dough into a disc and press it evenly into the bottom and up the sides of a 10-inch nonstick tart pan with removable bottom; if necessary, use a piece of plastic wrap to help keep the dough from sticking. Refrigerate the tart shell until firm, about 1 hour, or freeze for 30 minutes.
Preheat the oven again to 350 degrees F.
Line the tart shell with aluminum foil and fill with pie weights. Place the tart shell on a baking sheet and bake until the edges of the crust are barely golden, about 15 minutes. Carefully remove the foil and weights and continue to bake until the crust is golden brown all over, about 20 minutes. Cool completely, then gently remove the tart shell from the pan and onto a plate.
For the lemon curd filling: Melt the butter in a large microwave-safe bowl, using the butter paper to make sure the butter does not splatter, usually about a minute on 40 percent power. Then, add the sugar and salt and whisk together. Add the whole eggs and egg yolk and whisk again. Add the lemon zest and juice and whisk well. Microwave for 1 minute. Remove carefully and whisk. Continue to microwave in 1-minute intervals, whisking after each minute, until the mixture is thick. It usually takes between 2 to 5 minutes, depending on the microwave. Note that the mixture will get thin before it gets thick.
Carefully remove the bowl from the microwave and push the curd through a fine-mesh sieve into another bowl. Press a piece of plastic wrap directly onto the surface of the curd and refrigerate until set, at least 2 hours.
For the whipped cream: Place the whipping cream, sugar, vanilla and salt in the bowl of a stand mixer fitted with the whisk attachment and whip until soft peaks form.
To assemble the tart: Pour the lemon curd into the tart shell and spread evenly. Place the whipped cream in a piping bag fitted with a plain tip and pipe a border around the edge of the crust. Sprinkle with the reserved toasted coconut. Allow the tart to chill in the refrigerator for at least 2 hours before slicing.