Preheat oven to 375β degrees. Lightly grease a 13"x9" pan and set aside.
In a large bowl, combine chopped artichoke hearts, spinach, sour cream, mayonnaise and garlic powder. Stir well to combine.
Add mozzarella and parmesan to the bowl and stir well.
On a cutting board, unroll one tube of crescent rolls. Pinch all the seams to make one large rectangle. Spread half of the spinach artichoke mixture on the dough. Starting at a long end, roll up, jellyroll style. Cut the log into 8 pieces.
Repeat with the remaining crescent rolls and spinach artichoke mixture.
Place the 16 rolls in the prepared pan with the filling facing up.
Bake for 35-40 minutes until the top turns golden brown. If it starts browning too quickly, cover lightly with foil.