In a medium mixing bowl, mix the flour, baking powder, baking soda, salt and pepper.
Add in the eggs, olive oil, milk, 1/4 cup of the parmesan cheese, mozzarella and the pepperoni slices.
Line a 5 qt crock-pot with parchment paper.
Add one half the batter to the crock-pot, a layer of marinara sauce, and then the rest of the batter. Top with the remaining parmesan cheese.
Cover and Cook on HIGH for 2 hours or unitl the middle is cooked.
Serve and enjoy!