I made this before. I took a slotted serving spoon - one of the big plastic ones and moved the hamburger meat floating in grease to a bowl lined with paper towels. That's how i drain all my hamburger meat. Then you have to pat the top part with paper towels to get all of the grease out.
Maybe you didn't let it cook long enough?!?! It needs to cook until a knife or fork insterted comes out clean.
Also, once it comes out of the oven let it sit for about 15 mins. It will firm up more then too.
Mine was great. I served it with ketchup and mustard. I also added a pack of the ranch seasoning in mine. It was very good. I also do a taco version where I add taco seasoning and less heavy cream and sub sour cream for that....Top it with all your favorite taco toppings! Mmmmmm