In a medium bowl, whip the heavy cream and vanilla. When medium peaks start to form, add the brown sugar and creme fraiche. Beat until stiff peaks form; chill until ready to use.
In a medium mixing bowl, make the pudding according to package directions. Chill until the pudding sets, then mix in the lemon curd. Chill until ready to use.
Depending on the size and shape of your dish, you’ll want to divide your pound cake, pudding, raspberries, and whipped cream in half—reserve about 2/3 cup of cake and 1/4 cup of raspberries to garnish the top.
In a large glass bowl or parfait dish, add a layer of pound cake, followed by the pudding mixture, raspberries, and whipped cream. Repeat this once more, finishing the top layer of the trifle with a generous amount of whipped cream, garnished with cake, raspberries, pistachios, and shredded coconut.