Whisk together the cream cheese, sour cream, garlic, chili powder, red pepper flakes, spinach, and half of the mozzarella cheese in a medium bowl.
Once the mixture is smooth and homogenous, pour it into a large skillet.
Top the dip with the remaining cheese and bake the mixture for 20 minutes.
(Optional) Switch the oven to a high broil and continue baking the dip for 2-3 minutes, or until the top of the dip is golden brown.
Serve with veggies, chips, etc. and enjoy!
Notes
In my experience, this dip does not freeze well. Cream cheese based recipes can be frozen, but the texture changes significantly when thawed and reheated.
To store leftovers, transfer dip to an airtight container and refrigerate for up to 5 days.
Reheat in the microwave for 45-90 seconds, depending on portion size.
For fresh spinach, you will need about 3/4 of a pound of fresh spinach, cooked down to equal about 3/4 of a cup.