Another idea if you haven't made the cake yet, the recipe on the back of the bag of fresh cranberries makes a lovely cranberry/orange bread that could be served as a tea-cake. It's very moist, and bakes in a 9" loaf pan. I love it, make it every year, and everyone who tastes it raves about it.

Cut it into slices just before you leave, arrange on pretty plate, cover with plastic wrap and stick a bow on it.

If you haven't made the loaf yet, cut the recipe you found in half and put it into a 9" loaf pan. That should be about the right amount for a good-sized loaf (close enough at least for it to work). Or, check out this recipe, which is pretty basic for a loaf:
http://www.epicurious.com/recipes/food/views/Cranberry-Nut-Bread-13190

If you have made it and you've got your giant rectangle, try cutting it into diamonds or triangles to give it some interest. You can pile them on a plate and cover in foil or plastic wrap (with a bow on top if you want to make it look really wrapped). To cut a rectangle into diamonds, first cut rows length-wise. Then, make diagonal cuts across the straight rows. See this picture:
http://theshiksa.com/blog/wp-content/uploads/2010/03/Tishpishti-Sliced.jpg

Trim edges 1/4" from all four sides, then cut the coffeecake into neat 3" squares. (If it has a very tender crumb, it might be easier to cut it if it's been frozen for an hour or so.) Dust the squares witha thick layer of powdered sugar, then stack them into a tall pyramid onto a plate (disposable is fine, but a giftable holiday plate is better). If you can cut the squares diagonally in half to form triangles without it being reduced to crumbs, you'll be able to make the pyramid look more like a snowy fir tree.

Keep in mind that cutting the coffeecake will cause it to dry out quickly, so wrap it tightly in plastic and tie it with ribbon, letting the loosely-curled ends drape down so that it looks festive.