Preheat the oven to 400˚F. Remove the extra papery skin from the garlic bulb. Do not remove all of it, you want the garlic bulb to still be in tact. Slice off 1/4 inch from the top of the bulb so that you can just see the cloves. Place it on a sheet of foil then drizzle 1 tablespoon of the olive oil over top. Wrap up the foil so that the garlic is completely encased then bake it for 40-45 minutes until the cloves are soft and golden brown. Remove it from the oven and allow it to cool to room temperature. When the garlic has cooled, squeeze out the roasted garlic from the bottom of the bulb and set aside.
Pour the remaining 1/4 cup of olive oil into a liquid measuring cup with a spout. Add in the garlic powder, oregano, thyme, red pepper flakes, paprika, cumin, coriander and fennel seeds. Mix with a whisk until combined.
Arrange the racks in the oven so that one rack is placed at the lowest level and another rack is placed at the highest level. Preheat the oven to 450˚F. Uncover the dough and, with greased hands, use your fingertips to create dimples all across the surface of the dough. Give the spiced olive oil a final mix to re-distribute the spices the drizzle it over top the focaccia. Press the tomatoes into the dough, cut side up. Then sprinkle the red onion, feta, flaky salt, and cracker black pepper on top.
Place the focaccia on the lowest rack and bake it in the oven for 20-25 minutes until it has started to brown. Transfer it to the highest rack and bake it for 5 minutes until golden brown. To finish, broil it for 2-3 minutes. Remove the focaccia from the oven and allow it to sit in the pan for 10 minutes. Use a spatula to help lift the focaccia out of the pan then place it on a wire rack to cool. Slice and enjoy!