On one of my particularly greedy afternoons I was nibbling on a batch of store-bought coconut macaroons, and thought they were a little dry. I raided the fridge and found cream cheese and lime curd, so I put them both to good use. The idea for this came instantly, and the next day I had to get down to work. The trick to an utterly delicious macaroon base is to combine the coconut with melted marshmallows before baking. And since marshmallows are a great setting agent, I used them for the filling, too, so there is no need to bake it.
Preheat the oven to 350°F. Grease the base and sides of a 9-inch spring form cake pan and line with parchment paper.
For the coconut macaroon base:
Put half of the marshmallows into a heatproof bowl with 1 tablespoon of the water. Set over a pan of barely simmering water, and stir until the marshmallows melt into a thick goo. Add the coconut, still over the heat, and stir until well coated in the melted marshmallow.
Transfer to the cake pan and press it into the base and up the sides. (I find it far easier when I grease my hands with a little oil, and I prefer a more rustic, uneven edge.)
Bake the base for 15 minutes, until golden brown. This will puff up a little, so as soon as it comes out of the oven, press it down gently to compact it. Allow to cool.
For the filling:
Repeat the marshmallow melting process with the remaining marshmallows, and the remaining tablespoon of water. Once melted, remove from the heat and beat in the lime curd, then beat in the cream cheese. (It's easier to do this with a whisk, but don't whisk to aerate, just vigorously mix until smooth.)
Pour the filling over the cooled coconut base and refrigerate overnight. Don't be impatiently prodding this or prematurely slicing it; just forget about it until it sets completely. Sprinkle over the lime zest before serving.