Preheat oven to 350F degrees. Grease and flour a 9-inch cake pan or regular loaf pan.
In a medium bowl, whisk together 2 cups flour, 4 teaspoons baking powder, 1 Tablespoon sugar, ½ teaspoon oregano, ¼ teaspoon sea salt, and ¼ teaspoon black pepper (If you're using garlic powder, rather than fresh garlic, add ½ teaspoon here now). Set aside.
In another bowl, add ½ cup feta, ¼ cup peperconcinis, ¼ cup onion, ¼ cup black olives, ¼ cup green olives, 2 Tablespoons tomatoes, 1 ½ teaspoons mustard, 1 Tablespoon butter, 3 minced garlic (if using fresh) 1 egg, and 1 cup milk. Give these ingredients a quick stir.
Sprinkle the flour mixture over the wet ingredients and mix until incorporated.
Pour into the prepared pan. Smooth batter to the sides and sprinkle with ¼-½ cup chopped prosciutto and extra tomatoes. Add 2 Tablespoons shaved or grated Parmesan cheese. Toss 1 Tablespoon capers on top and if desired, add additional black pepper.