Pre heat oven to 375℉
Butter and flour 9" x 9" baking pan. Cut a piece of parchment paper to line the bottom of the pan.
In a large mixing bowl, whisk together 1 1/2 cups flour, 2 tsp baking powder, kosher salt and freshly ground black pepper.
In another bowl, mix together 4 large eggs and 1 sprig finely chopped rosemary leaves. Gradually whisk in 1/2 cup olive oil, then 3/4 cup milk and mix until combined.
Add wet ingredients to dry ingredients and mix gently until combined.
Fold in 1 whole piquillo pepper, chopped, 3-4 slices salami, chopped, 1/2 cup coarsely grated Gruyère cheese and 3-4 whole coarsely chopped Kalamata olives. Do not overmix, just blend until the ingredients are evenly spread in the batter.
Pour batter in the prepared pan and spread to smooth the top.
Bake in the middle rack, rotating pan halfway through. Bake for 45 to 50 minutes or until a wooden skewer inserted in the middle comes out clean.
Remove pan to a rack and allow it to come to room temperature. Turn out cake from pan, re move parchment paper and cut into 1" squares or 2" bars and serve as an appetizer.
Sprinkle top with coarsely grated parmesan or gruyere cheese.