Cook bacon in a large skillet over low heat until crisp, then remove and reserve drippings; once cooled, roughly chop bacon.
Slice chicken breasts thinly and season with salt, pepper, onion powder, and Italian seasoning.
Sear the chicken slices in bacon drippings over medium-high heat until golden and cooked through, then cube after resting.
Boil pasta in salted water until al dente; drain and set aside.
In the skillet, melt butter and sauté minced garlic until fragrant.
Stir in flour to form a roux, then gradually whisk in half and half to create a smooth sauce.
Add ranch seasoning mix and shredded cheddar cheese to the sauce, stirring until melted and smooth.
Combine cooked pasta and chicken into the sauce, mixing well.
Top with chopped bacon and serve warm.