Preheat oven to 350℉. Lightly coat a casserole dish with nonstick cooking spray.
Place the bottom half of your mini sesame burger buns into the casserole dish lining them up making sure there is no space between the two. Evenly spread the marinara sauce across all the buns, then top each slider with two slices of pepperoni and one slice of mozzarella cheese. Top the mini sliders with the top of the bun.
Bake in the oven for 15 minutes or until the tops have a golden brown color. Garnish with chopped parsley and serve while hot.