Preheat the oven to 375°F (190°C). Lightly grease a small 8x8 baking dish.
After thawing and rinsing the spinach, squeeze out as much excess moisture as possible using paper towels or a clean kitchen towel.
In a medium bowl, combine the cream cheese and sour cream until smooth.
Stir in spinach, mozzarella, Parmesan, garlic powder, onion powder, salt, and pepper until evenly combined.
Spread the mixture evenly into the prepared baking dish. Bake for 20-25 minutes, or until hot and bubbly around the edges.
Sprinkle with red pepper flakes before serving. Serve warm with sliced baguettes, tortilla chips, or crackers.