Thaw frozen chopped spinach completely (overnight in fridge or microwave according to package). Place spinach in several layers of paper towels or a clean kitchen towel and squeeze firmly until most moisture is removed. Measure 2 cups of squeezed spinach.

Prepare artichokes

Drain canned artichoke hearts well, then pat dry with paper towels. Roughly chop and measure 1 cup.

Preheat oven to 375°F (190°C). Lightly grease a 9-inch (23 cm) baking dish or a shallow oven-safe skillet with 1 tablespoon olive oil.

Make the dip

In a large mixing bowl, add 8 oz softened cream cheese. Break up with a spatula until smooth.

Add 1 cup sour cream and 1 cup mayonnaise to the bowl. Stir until well combined and smooth.

Stir in the squeezed spinach (2 cups) and chopped artichoke hearts (1 cup) until evenly distributed.

Add 1 cup shredded mozzarella and 1 cup grated parmesan to the mixture. Reserve the topping cheeses (0.5 cup mozzarella + 2 tbs parmesan) separately for later.

Mix in minced garlic (2 cloves), 1 tablespoon lemon juice, 1 teaspoon salt, 1 teaspoon black pepper, and 1/4 teaspoon crushed red pepper flakes. Taste and adjust seasoning if desired.

Assemble & bake

Transfer the prepared dip mixture into the greased 9-inch baking dish and spread into an even layer.

Sprinkle the reserved topping of 1/2 cup shredded mozzarella and 2 tablespoons grated parmesan evenly over the top.

If using, evenly sprinkle 1/4 cup panko breadcrumbs over the cheese for a crisp top.

Bake in preheated 375°F (190°C) oven for 20–25 minutes, until edges are bubbling and the top is golden brown. If top browns too quickly, tent loosely with foil.

For a browned finish, switch oven to broil for 1–2 minutes — watch carefully to avoid burning.

Finish & serve

Remove dip from oven and let rest for 5 minutes to firm slightly.

Garnish with chopped fresh parsley (1 tablespoon) before serving.

Serve warm with baguette slices, pita chips, or fresh vegetable sticks.

Leftovers: store in an airtight container in the refrigerator for up to 3 days. Reheat in oven at 350°F (175°C) until warmed through, about 10–15 minutes.