Trim the tops off the two heads of garlic so that the cloves are exposed. Place on a piece of parchment paper or aluminum foil. Drizzle the cloves with the olive oil and season with salt and pepper. Close the parchment with butcher’s twine and place in an oven safe dish. Roast in the oven for 30 minutes. Meanwhile, set the pizza dough to rest at room temperature for about 30 minutes.
Preheat a waffle baker. On a lightly floured surface, divide the pizza dough in half. Roll each piece into 7-inch rounds. Using a pastry brush, lightly brush the waffle baker with clarified butter or ghee. Dust any excess flour off the pizza dough, then place in the waffle baker, stretching it to fit, if necessary. Close the waffle baker lid, then repeat on the other side. Bake the pizza dough for about 6 minutes, then carefully transfer to a wire rack.
Squeeze the roasted garlic heads, extracting the garlic into a dish. Mash with a fork. Spread the garlic over the baked pizza dough, getting it into each nook and cranny. Trim the rind from the brie and spread it generously over the garlic. If you wish for the beets to be warm, place it on top of the brie. Season with salt and pepper. Bake in the oven until the brie is melted, about 6-8 minutes. Top the pizzas with arugula, and lightly drizzle with a little olive oil. Garnish with red pepper flakes and serve immediately.