Bring a large dutch oven full of water to a boil, then add the macaroni noodles. Boil the pasta until al dente following the package instructions; then drain and set aside.
Place the dutch oven back on the stove over medium heat and melt the butter. Whisk in the flour and cook for 1 minute.
Slowly stream the warmed milk and heavy cream into the pot, whisking constantly, until all of the liquid has been added. Then whisk in the spices. Bring it to a simmer, then reduce the heat to low.
Slowly start whisking in the cream cheese and shredded cheeses a handful at a time. Whisk until the cheese is completely melted, then remove the pot from the heat and stir in the cooked elbow noodles.
In a small pan, melt the butter, then stir in the garlic and Worcestershire sauce and cook 1 minute until the garlic is fragrant. Toss in the crushed crackers and fresh thyme and cook until the crackers are golden brown, about 3-5 minutes.
Serve the mac and cheese hot with the buttery crumb topping.
To make baked mac and cheese, preheat the oven to 350 F/180 C. Melt the butter for the crumb topping and combine it with the crackers, garlic, Worcestershire sauce, and fresh thyme. Sprinkle the crackers over the top of the macaroni and cheese. Bake for 10-15 minutes, or until the crackers are golden brown. Serve immediately.