In a large pot, bring salted water to a boil.

Cook your macaroni shells according to package instructions. Drain, reserve some of the pasta cooking water.

Add your bacon to a sheet tray, cook until crispy at 385 degrees, or according to package instructions.

Once cooked, chop the bacon into small pieces, set aside.

Tear your white bread pieces roughly onto a sheet tray. Generously spread oil on the bread, and any seasoning if desired. Place into the oven until golden.

Add cooked bread to a food processor, process until you reach desired breadcrumb consistency.

In a large saucepan, add your butter. Once melted, add your sour cream, stir until smooth.

Stir in the sour cream, followed by the Mexican cheese and cheddar cheese.

Once the sauce is emulsified, add your cooked macaroni shells to the sauce, along with a splash of the pasta cooking water. Stir to combine.

Top your macaroni and cheese with the remaining mexican cheese spread, and place under the broiler until melted and golden.