Make the cake, curd, and whipped cream as directed. Be sure to refrigerate the whipped cream so it's nice and thick.
When the cakes have cooled to room temperature, turn one out onto a serving platter and spread the curd on top, leaving a roughly 1/2" gap around the edges.
Turn the other cake out on top, then cover the whole thing in whipped cream. If it's too thick to spread, you may have to whisk it or let it thaw a bit.
Keep any leftover cake covered in the refrigerator for up to 3 days.