Preheat the oven to 350˚F (175˚C). Spritz a 9x5-inch loaf pan with cooking spray, or rub it lightly with oil. Line it crosswise with a piece of parchment paper (this will make it easy to remove the loaf later).
In a large bowl, whisk together the dry ingredients. Use your fingers to break up any clumps of almond flour.
In a liquid measuring cup, combine the warm water, vegetable oil and apple cider vinegar. Pour the wet ingredients over the dry ingredients. Whisk well until everything is incorporated, then switch to a rubber spatula. Stir until smooth—the dough should feel smooth and just a tiny bit tacky.
Transfer the dough to the prepared pan. Using slightly damp hands, press the dough gently into an even layer—try not to compress the dough too much.
Bake the bread until it’s golden brown evenly on the top and a toothpick inserted in the center comes out clean, about 45-50 minutes (don’t under-bake the bread, otherwise the center might not cook through). Let the loaf cool in the pan on a rack for 5-10 minutes (the top might slump slightly) then remove it from the pan and let it cool completely before slicing.
You can serve this bread as-is, but I prefer to toast it! Spread it with your favorite fixings, and enjoy.