biscuits

Also known as cookies. Digestive, rich tea, shortcake, lincolns, custard creams, bourbons, oreos - everyone likes some kind of biscuit (cookie). For crushing for a biscuit base stick to a plain (ie no cream or chocolate) biscuit. Slightly sweet biscuits like digestives (they're like Graham Crackers) work best.

Icecream cake

Icecream cakes - anything goes as long as icecream is involved somewhere. As easy or as complicated as you like, it's impossible to be wrong and guaranteed to taste good (just make sure you keep it cool!)