Heat olive oil in a skillet over medium-high heat; saute scallops until golden brown and cooked through, 2 to 3 minutes per side. Remove skillet from heat.
Place bacon in a large skillet and cook over medium-high heat, turning occasionally, until evenly browned, about 10 minutes. Drain bacon slices on paper towels; roughly crumble.
Bring a large pot of lightly salted water to a boil; add penne and cook, stirring occasionally, until tender yet firm to the bite, about 11 minutes. Drain.
Mix Cheddar cheese soup, Cheddar cheese, milk, and garlic salt together in a bowl. Add scallops, bacon, and pasta; mix well. Pour pasta mixture into a 2 1/2-quart baking dish.
Stir bread crumbs and butter together in a bowl; sprinkle over pasta mixture.
Bake in the preheated oven until bubbling and topping is lightly browned, 25 to 30 minutes; season with salt and pepper.
