Spinach artichoke dip

Ingredients

• 2  cups  (8 ounces) shredded part-skim mozzarella cheese, divided
• 1/2  cup  fat-free sour cream
• 1/4  cup  (1 ounce) grated fresh Parmesan cheese, divided
• 1/4  teaspoon  black pepper
• 3  garlic cloves, crushed
• 1  (14-ounce) can artichoke hearts, drained and chopped
• 1  (8-ounce) block 1/3-less-fat cream cheese, softened
• 1  (8-ounce) block fat-free cream cheese, softened
• 1/2  (10-ounce) package frozen chopped spinach, thawed, drained, and squeezed dry
• 1 teaspoon horseradish
• about 5 drops of Tabasco sauce