Preheat oven to 425 degrees F. Use about ½ tablespoon of the butter to thoroughly grease a 6.5 inch cast iron skillet or a 6 inch cake pan. Set aside.
In a mixing bowl, combine the flours, baking soda, salt, sugar and caraway seeds. Stir well so that everything is evenly distributed.
In another small bowl or in a two cup glass measure, whisk together the egg, maple syrup and vinegar.
Add the egg mixture to the almond meal mixture. It should be thick, but not quite a dough -- more of a thick batter. Scrape it into the prepared skillet.
Put the skillet in the hot oven.
After about 2 minutes, reduce the heat from 425 to 350 and bake for 25 to 27 minutes or until bread appears set and crispy around the edges.