1. Sprinkle the yeast over very warm water (not boiling or hot), then sprinkle the sugar over the yeast. Resist the urge to stir. Cover, and wait ten minutes for the yeast to rise and become frothy/bubbly over the water and sugar.
2. Melt butter.
3. Blend vital wheat gluten, almond flour, coconut flour, flaxseed meal, and dark rye flour in a medium bowl.
4. Stir 1 1/2 cups of the flour mixture into the yeast mixture.
5. Stir for 1 minute.
6. Let stand for 10 minutes.
7. Mix the salt and baking powder into the flour mixture.
8. Stir the vinegar into the melted butter.
9. Stir the butter mixture into the dough until the liquid is absorbed.
10. Slowly mix in the remaining flour mixture. Towards the end, set aside the spoon and mix in by hand.
11. Cover the dough and let it rest for 10 minutes.
12. Turn the dough out onto a lightly almond floured surface and knead for 10 minutes until elastic and smooth.
13. Grease a large bowl with butter.
14. Form the dough into a ball and add it to the greased bowl. Flip it so that it is buttered on both sides.
15. Cover with a towel and let rise until it has doubled in size (1-2 hours). You'll know it's ready when you touch the dough and the fingerprints remain.
16. Punch down with a balled hand, shape into a loaf and place in a greased loaf pan.
17. Let rise for 40 minutes, until it has almost doubled in bulk again.
18. Preheat oven to 350 degrees F.
19. Bake for 40-45 minutes until nicely browned. When you tap the bottom you should hear a hollow sound.
20. Turn the pan on it's side and cool for 2 minutes.
21. Slide the loaf out onto a wire drying rack and turn the loaf to the other side.
22. Let cool completely.