In a large pan, heat oil over medium. Add onion and sauté until lightly browned, 5 to 8 minutes; add the garlic in the last 30 seconds and stir to combine.

Add spinach and cook until completely wilted, 5 to 8 minutes. Transfer to a colander; drain, pressing to release all excess liquid.

In the same pan, warm milk over high heat. Whisk in cream cheese until melted, about 3 minutes. Add spinach, chopped artichoke hearts, Worcestershire sauce, hot sauce, and the mozzarella; stir to combine. Stir in the bacon and season with salt and pepper. Simmer over medium low heat until ready to serve. Transfer to serving dish and serve alongside a sleeve or two of Ritz Crackers.