Preheat your oven to 400°F (200°C).
In a small bowl, mix the softened cream cheese, olive oil, garlic powder, oregano, and black pepper until smooth.
Spread the cream cheese mixture evenly over each flatbread.
Layer the salami, prosciutto, cheddar cheese, and brie cheese on top of the cream cheese spread.
Scatter the mixed olives and cherry tomatoes over the flatbreads.
Place the flatbreads on a baking sheet and bake in the preheated oven for 10-12 minutes, or until the cheeses are melted and the edges are golden brown.
Remove from the oven and let cool for a minute before topping with fresh arugula and drizzling with balsamic glaze.
Slice into pieces and serve warm.