Soak the sunflower seeds in hot water for 30 minutes.
Preheat the oven to 180ºC and line a 20 cm square baking dish with baking paper.
Add the dates, oats, almonds and salt to the food processor and process until you've got a grainy flour. Add the melted coconut oil, and pulse until you've got a bit of a dough going on. Pinch some of it between two fingers: it should stick. If it's too dry, add a little more melted coconut oil.
Transfer the mixture to the lined baking dish, then spread it out and pat it down firmly and evenly.
Bake in the preheated oven for about 20 minutes until it's changed colour a bit. Remove and cool, while you prepare the filling.
Drain the sunflower seeds, and place in the blender along with the rest of the filling ingredients (coconut cream, sugar, arrowroot starch, lime juice and zest, and salt). Blend for a couple of minutes until nice and creamy.
Pour onto the prebaked crust in the baking dish, and tap the dish lightly on the counter to distribute evenly and get any air bubbles out.
Bake in the preheated oven for about 20 minutes, until the edges are pulling away very slightly.
Remove from the oven, and cool to room temperature before transferring to the fridge, to cool for a couple of hours, before serving.