Preheat the oven to 375°F. Line an 8x8-inch baking pan with parchment paper and brush the paper lightly with olive oil.
In a large bowl, whisk together the almond flour, psyllium husk powder, baking powder, salt and garlic powder until there are no lumps.
In a second bowl, whisk the eggs, 1/4 cup olive oil, warm water and apple cider vinegar until well blended.
Pour the wet ingredients into the dry ingredients and stir until a thick, sticky dough forms. Let it rest for 5 minutes so the psyllium can absorb the liquid and the dough firms up.
Spread the dough evenly in the prepared pan. Oil your fingertips and press deep dimples all over the surface.
Drizzle the 2 tbsp olive oil over the top so it pools in the dimples, then scatter on the rosemary and flaky sea salt.
Bake for 22-25 minutes, until golden brown on top and firm in the center. Cool in the pan for 10 minutes before lifting out and cutting into squares.