Add cream cheese, strained spinach, sour cream, Worcestershire sauce, minced shallot, chopped water chestnuts, garlic powder, salt, and cayenne pepper (optional) to a large bowl and stir until well combined.
1 8 ounce package cream cheese, 1 10 ounce package frozen chopped spinach, thawed , 1 cup sour cream, ½ tablespoon Worcestershire sauce, 1 shallot, finely minced, 4 ounces water chestnuts, finely chopped, ½ teaspoon garlic powder, ½ teaspoon salt (plus more, to taste), 2-3 dashes cayenne pepper