A great drink for Autumn with apples and pumpkins together.
Personally I don't think the order matters, but if you'd like to "float" the beer (especially if you use a stout instead of lager) then pour in cider first. Note that this is "hard" stuff, not apple juice. My "parts" are guessed based on ml, but beer and cider are equal, about 1/2 pint each.
Then, finally, pour in a shot of delicious pumpkin liqueur in place of the traditional blackcurrant cordial. Makes a lovely red-orange beverage, great for Halloween parties :)