Reduce the Marinara. Pour the marinara sauce into a small saucepan over medium heat. Simmer, stirring occasionally, for 8–10 minutes until it thickens to a spreadable, paste-like consistency. It should hold its shape when spread. Remove from heat and set aside.
Mix and Portion the Meat. While the marinara is reducing, combine the ground beef and ground Italian sausage in a bowl. Mix gently until just incorporated — don't overwork. Divide into 8 equal portions (about 3.5-4 oz each) and roll loosely into balls.
Crisp the Pepperoni. Heat your griddle to medium-high. Lay pepperoni slices flat and cook for 1–2 minutes until they curl into cups and develop crispy, slightly charred edges. Remove and set aside.
Toast the Ciabatta. Brush the cut sides of the rolls with a small amount of olive oil. Place ciabatta rolls cut-side down and toast for 2–3 minutes until golden with some char on the edges. Remove and set aside.
Smash the Burgers. Place a meat ball on the hot griddle and immediately press down firmly with a burger press or heavy spatula, smashing to about 1/4-inch thickness. Season the top with salt and pepper. Cook for 2–3 minutes until a deep brown crust forms on the bottom. Repeat for the other burger balls. (For smash burgers, I find it best to do 4-6 patties at a time on the griddle.)
Flip and Add Cheese. Flip the burger patties and immediately place a slice of provolone on top of each patty. Cover with a dome or foil and cook for another 1–2 minutes. Use an instant-read thermometer — the internal temperature must reach 160°F (71°C) due to the pork in the blend.
Assemble the Burgers. Spread a generous spoonful of marinara chutney on both the top and bottom ciabatta buns. Place one patty on top of another to form double stacks. You should have 4 burgers total, each consisting of 2 thin smash burger patties. Place a pizza burger on the bottom bun, top with crisped pepperoni cups and a pile of banana peppers. Cap with the top bun and serve immediately.