Heat the oven to 350°F.
Mix together the beef, salt, pepper, garlic powder, onion powder, and thyme in a medium bowl. Using your hands, pat down the mixed beef flat into a 9x13-inch rimmed baking dish. Bake for 20 minutes. Set the cooked beef aside on a plate. Clean and dry the baking dish.
Slice the rolls in half lengthwise. Put the bottom half of the rolls in the baking dish. Place the slab of cooked beef on top of the roll bottoms followed by the brie slices and rounds of cranberry sauce. Top with the layer of remaining roll tops.
Bake for about 10 minutes, until the cheese is melted and the tops of the rolls are light golden brown.
Slice into individual sliders and serve warm.