Preheat oven to 400° and grease a 10-inch oven proof, non-stick skillet with cooking spray.
Whisk together olive oil, butter, garlic, parmesan, parsley and salt.
Roll out biscuits to flatten-slightly, then cut each one in half. Brush each slice with butter mixture, sprinkle lightly with pepperoni and mozzarella. Roll the dough up lengthwise and pinch edges together to seal, then tie the dough to knots.
Put stuffed knots in the skillet. Brush remaining butter mixture onto dough and sprinkle with more pepperoni and mozzarella.
Bake until the cheese is melted and the biscuits are cooked through for18-20 minutes.
Serve warm with marinara.