Preheat oven to 375 degrees F. Lightly oil a pie plate or coat with nonstick spray.
In a large bowl, combine artichoke hearts, spinach, sour cream, mayonnaise, garlic powder and onion powder; season with salt and pepper, to taste. Stir in Castello Havarti Cheese. Unroll pizza dough, pressing perforations to seal into approximately a 13x18-inch rectangle. Top with artichoke mixture.
Starting at the shortest side, roll up, pressing the edges to seal. Cut in eighths. Place, cut side down, onto the prepared pie plate. Brush with egg.
Place into oven and bake until golden brown, about 20-25 minutes.
Serve immediately, garnished with parsley, if desired.