Peel sweet potatoes and roughly cut into small pieces.
In a large bowl, combine flours, salt and yeast. In a separate bowl mix warm water, maple syrup, olive oil, and sweet potatoes, stir until smooth and add to dry ingredients.
Mix with a wooden spoon until you have a wet sticky dough, about 1 minute. The dough should be sticky so if it is not you can add 1-2 TBS of water one at a time as needed.
Add pecans and mix until incorporated.
Cover bowl with plastic wrap and allow dough to rise at room temperature for 2 hours. Then place in covered dough in refrigerator overnight to allow to develop and ferment.
On baking day: Remove dough from refrigerator. Use a rubber spatula to ease it out of the bowl onto a work surface that has been generously coated with flour. Lightly flour your hands and gently form dough into a ball.
Place a large tea towel (not terry cloth or it will stick) on the work surface and generously dust it with flour, wheat bran, corn meal-- I used flour. Lightly dust the dough ball with flour and place on the tea towel. It may look like a lot of flour (or wheat bran/corn meal if that is what you are using) but it will prevent the dough from sticking to the towel.Bring the edges of the towel together and fold over dough ball. Return tea towel covered dough ball to bowl and allow to rise at room temperature for another 1-2 hours, it should almost double in size again.
30 minutes before the end of the second rise preheat oven to 450 degrees F. and place the rack in the bottom 1/3 of the oven. Place a covered heavy pot in the center of the oven to heat. I used a 3.5 QT cast iron Dutch Oven.
When the dough has completed the second rise: Carefully remove the the covered pot from the oven and remove the lid. Wear potholders here because the pot and lid will be very hot. Unfold the tea towel and gently dump the dough ball into the pot. Replace the lid and return to the oven. Bake for 30 minutes.
Remove lid and bake for another 15 minutes or so or until loaf is golden brown but not burned. Carefully remove pot from oven and place loaf on a rack to cool.
Enjoy! This bread is at it's best for 2-3 days, recommend storing in a brown paper bag.