Measure all ingredients using a metric kitchen scale.
Mixing
Mix on low the whole wheat flour and instant yeast in bowl of electric mixer with whisk attachment.
Heat buttermilk to no warmer than 110 degrees. Hint: I used one cup of 2% milk and added 1.5 tsp apple cider vinegar since I did not have any buttermilk.
Mix honey into warm buttermilk.
Pour buttermilk mixture into bowl of an electric mixer with the whole wheat flour & yeast.
Mix with whisk attachment on medium-low speed until ingredients are moistened. Scrape sides and mix again.
Rest mixture for 15 minutes.
Meanwhile, melt butter and allow to cool slightly.
After 15 minutes, pour melted butter and egg into bowl of the electric mixer with the whole wheat mixture.
Mix with whisk attachment on medium-low speed until ingredients are just incorporated.
Switch to dough hook and add salt and all but 2 T of AP flour.
Mix on low for 2 minutes or until no dry ingredients remain.
Mix on speed two for 5 more minutes until dough pulls from the sides of the bowl but sticks to the bottom. Adding the extra 2 T of flour, if needed. Hint: Do not add too much flour or knead these too long. It will make the final rolls tough rather than soft.
Bulk Fermentation
Dump dough onto counter, knead a few times just into a smooth ball.
Spray a container or bowl with spray oil.
Place dough ball into container.
Cover with plastic wrap or cover, set aside and allow to rise in a warm place until doubled, may take up to 1½ hours.
Folding (sometimes called punching)
Dump doubled dough onto counter top. Gently press dough into a loose rectangle about 30 x 23 cm (12" x 9").
Roll dough loosely into a 12" log.
Dividing
Using a Bench Scraper, cut the log into 12 equal pieces.
Pre-Shaping or Rounding
Pull outside of each piece of dough into the center. Turn dough ball over and tighten by pulling towards you, turn, pull until you have a tight ball. Repeat with each of 12 pieces.
Rest the rounded dough balls on the counter for few minutes while you prepare the baking pan.
Prepare the baking pan lightly with spray oil or butter.
Make-up and Panning
Give the dough balls one more tighten. Place them into the prepared pan 3 across and 4 down, spaced evenly.
Cover pan with plastic wrap.
Proofing
Set rolls aside to proof in a warm area until doubled in size, may take up to 45 minutes. Rolls should be touching slightly.
Baking
Preheat oven to 375° F / 190° C.
Mix egg with a few drops of water.
Using a pastry brush, lightly coat the doubled rolls with egg wash being careful not to deflate them.
If desired, sprinkle the tops of the rolls with sesame seeds.
Place rolls into the oven and bake for 15 minutes. Turn pan 180° and continue to bake for 10 more minutes until they are golden brown on top and bottoms are browned.
Cooling
Cool buns for 10 minutes in pan, pull apart and serve warm.