Remove your cold fermented dough from the refrigerator and flip it out of the banneton onto a sheet of parchment paper. Work quickly and confidently as the cold dough is easier to handle.
Using a sharp knife, trim a section of dough from each long side of the loaf. These two trimmed pieces will become the ears, tail, and feet, so set them aside on the parchment.
Take each trimmed piece and divide it into thirds. The top two thirds of each piece will become the ears. Shape them gently with your hands, keeping the natural taper of the cut to form an elongated oval with a pointed tip. Set the remaining bottom third pieces aside for the tail and feet.
Cut a piece of butcher’s twine approximately 8 inches long and slide it underneath the entire loaf, positioning it about 3 inches in from the end of the loaf where the head will be.
Place both ears seam side down on top of the loaf at the head end, with the pointed tips facing toward the middle of the loaf and the rounded bases sitting about 2 to 3 inches in from the edge of the dough. Dab a small amount of water onto the bottom of each ear before pressing them gently into place to help them adhere.
Bring the twine up between the two ears and tie it into a loose bow. The dough will expand significantly during baking so the twine must have room to give.
Roll one of the reserved small dough pieces into a round ball and press it onto the lower portion of the loaf to form the tail. Dab water underneath before pressing into place.
Take the remaining reserved piece and divide it in half. Tuck both small pieces underneath the back edge of the loaf so they peek out slightly to form the feet. Use a small dab of water to help them adhere.
Mix a small pinch of red rice yeast powder with 1 to 2 drops of water to form a thin paste. Use a small brush to paint the interior of each ear generously, painting a little bolder than you think you need as the color deepens during baking.
On the face area of the loaf, paint a wide V shape using the red rice yeast paste to mark where the nose and mouth will be.
Line your loaf pan with parchment paper and carefully transfer the assembled bunny into the pan.
If using a second loaf pan as a lid, place it inverted directly on top. If using aluminum foil, mold a sheet of foil around the outside of an inverted loaf pan to create a domed lid, then place it over the pan and tuck the edges around the outside to create a seal.
Bake at 450 degrees Fahrenheit with the lid on for 25 minutes, then remove the lid and continue baking for an additional 15 minutes until the crust is deep golden brown. If the ears begin to darken too quickly, lay a piece of aluminum foil loosely over the top for the remainder of the bake.
Remove the bunny from the oven and allow it to cool slightly before adding the face details.
Mix a fresh small batch of red rice yeast paste, slightly thinner this time. If any ear color needs to be touched up, brush it on now. For the rosy cheeks, dab your brush into the paste, wipe most of it off, then swirl it onto the cheek area in a circular motion moving outward. Use your fingers to blend it in slightly for a soft natural look.
Mix a small pinch of food-grade activated charcoal powder with 1 to 2 drops of water to form a thin paste. Wrap a small length of twine around the tip of a toothpick to create a thicker line. Dip it into the charcoal paste and draw two simple curved lines on the face for the sleepy closed-eye look.
Use the same charcoal toothpick to add a small amount of shadowing just underneath the V to define the nose, then draw a small line down the center at the bottom of the V to emphasize the mouth.
Allow the bunny to cool completely before removing the twine. The indentation left by the twine adds to the bunny shape.