Preheat oven to 350 degrees. Brown ground beef and drain.
Spread cream cheese into an ungreased shallow 1-qt. baking dish. Add 1 cup cooked ground beef, pizza sauce and 5 of the pepperoni slices (leave one for the topping). Add mozzarella cheese.
Bake for 20 minutes. Remove from oven, stir until combined, and top with remaining pieces of pepperoni and ground beef.
Serve warm with pepper and baguette.
Make ahead tip: Assemble the dip in advance, refrigerate it, and then bake it right before serving.