Set your oven to 350°F (175°C) to preheat.
Cook the ground beef in a skillet over medium heat until browned.
Remove any extra fat, then mix in the marinara sauce, Italian seasoning, salt, and pepper.
Add cauliflower rice and half of the shredded mozzarella to the skillet and stir well.
Pour this mixture evenly into a baking dish.
Sprinkle the remaining mozzarella over the top and arrange the pepperoni slices.
Place in the oven and bake for 25 to 30 minutes until the cheese is melted and golden.
Allow it to rest a few minutes before slicing and serving.