Pizza Rustica (Traditional Italian Easter Pie)

Ingredients

• 500g plain white flour
• 3 eggs + 1 beating for brushing
• 250g butter
• ¼ cup iced water
• 1 tsp salt
• 1 tsp baking powder
• 10 large eggs
• 300g ricotta cheese
• 2 cups mild salami, cubed into small pieces
• 1 cup provolone cheese, cubed into small pieces
• 1 cup mozzarella cheese, grated
• 1 cup parmigiano cheese, grated
• Pepper to season