Preheat the oven to 375 degrees. In a large skillet, cook the garlic in the EVOO over medium-low until golden, 3 minutes. Transfer to a cutting board; finely chop. Add the breadcrumbs and the lemon zest to the skillet; toss to coat in the garlic oil. Cook over medium-low until golden, 5 minutes.
In a bowl, mix the artichoke hearts, spinach, cream cheese, Parmesan, onion, mayonnaise, lemon juice and chopped garlic; season. Spread in a 10-inch foil-lined baking dish; top with the breadcrumbs. Bake until dark golden, 30 minutes. Serve with baguette slices.