My Mum's favourite is Pavlova, we make it the day before and it only takes a few minutes to add cream and fruit before serving. This Sunday however I'm doing her sticky toffee pudding in slow cooker, it can be done the day before and just make the sauce before serving.
My step father in law is allergic to chocolate so I should be good at this... Pavlova and sticky toffee pudding are great suggestions, and eton mess if your pavlova falls apart as mine often does.... Lemon posset (dead easy, only 3 ingredients), banoffee pie (can have cocoa on the top), Nigella does an amazing Baileys Tiramisu but that does have cocoa on the top as well... Cheesecake.... Apple crumble.... Treacle tart... I can send you links to recipes for most of these if you want them.... Caramel fondants.... There are probably hundreds more
Hmm, I have taken to a packet of Just Roll puff pastry, rolling it into a rectangle (it sort of comes that way anyway), slice 3-4 apples (eating) thinly then put them on in rows with a small overlap. Using a pastry brush, brush on apricot jam, then cook in hot oven (I use the roasting oven of an Aga, which is the hottest) for 20 mins or til gently browned. You can make it in advance and re heat for 10 minutes on the day. We serve with Crete fraiche or clotted cream or custard. Best of luck!