Preheat the oven to 350°F. Bring a large pot of water to a boil and cook the frozen spinach for about 4-5 minutes. Drain and let cool, then squeeze out all moisture with a kitchen towel. Set aside.

In a very large pan, melt the butter over medium heat. Add the shallots and garlic, stirring frequently for 2-3 minutes until softened and fragrant, but not too browned.

Stir in the flour until smooth and begins to turn light brown. Stir in the half and half and vegetable broth, bringing to a simmer over high heat until thick. Stir frequently to keep it smooth.

Add in the spices and cream cheese, stirring until smooth. Mix in the drained spinach until fully combined. Adjust seasoning with salt and pepper as needed.

Transfer to a baking dish and bake at 350°F for about 15 minutes or until golden brown on top.