Preheat oven to 350 degrees.
In a large mixing bowl whisk together all of the dry ingredients.
In a separate large mixing bowl whisk together all of wet ingredients.
Gradually ladle in small amounts of the wet mixture into the dry mixture, mixing until you have a pizza dough like consistency. Save the remaining wet mixture for braising and glazing during cooking.
Knead the dough in the mixing bowl for a couple of minutes to thoroughly incorporate all of the ingredients and create texture. It should be dense and difficult to pull apart.
Lightly coat a 13 x 9 inch baking pan or casserole dish with grapeseed oil.
Using a knife separate the dough into two manageable portions. Stretch and shape each portion into two "half rack" sized pieces at least one inch thick.
Lightly coat each piece in grapeseed oil and place side by side in the baking dish with an equal amount of space surrounding on all sides.
Pour some of the remaining wet braising mixture onto the seitan to coat and surround in a shallow bath.
Bake in the oven for 30-45 minutes until a crust has developed on top.
Carefully flip each piece of seitan and add remaining wet mixture to coat and surround. Bake for another hour.
Flip and seitan again and baste with the liquid in the pan, repeating this process every 20 minutes until the liquid becomes a thick glaze.
Remove seitan from the oven and allow to cool for 20 minutes to an hour.
Once cooled place in refrigerator overnight (recommended) or continue on with the grilling.
Heat a grill pan over med-high heat.
Baste the seitan pieces with the previously prepared BBQ sauce and place on the grill pan. Grill for a few minutes to develop grill lines.
Flip seitan and grill a few more minutes.
Remove seitan from grill and place on cutting board or platter. Slice into "riblets" and serve with remaining BBQ sauce.