Preheat the oven to 350°F and line a baking sheet with foil.

Slice the connected rolls in half horizontally as one piece, keeping top and bottom intact, and set the bottom half in the pan.

Spread the olive salad evenly over the cut side of the bottom half, letting the oil soak in slightly.

Layer the salami, ham and mortadella over the olive salad, covering edge to edge.

Lay the provolone over the meat, then set the top half of the rolls back in place.

Stir together the melted butter, garlic powder and oregano, then brush over the tops of the rolls.

Cover loosely with foil and bake for 10 minutes, until the cheese has melted.

Uncover and bake 3 to 5 minutes more, until the tops are lightly golden.

Rest for 2 minutes, then cut along the roll lines into 12 sliders and serve warm.