1 1/2 cups salted butter, softened
1 1/4 cups milk
1 cup dark brown sugar
1 package active dry yeast
1 cup chopped pecans
1/4 cup honey
1/2 cup plain Greek yogurt
2 1/2 cups confectioners’ sugar
1 tablespoon and 2 teaspoons cinnamon
2 tablespoons orange juice
1/2 teaspoon salt
1 teaspoon vanilla
4 1/2 cups (plus more if needed) whole-wheat pastry flour
In a small saucepan, heat the milk and butter (1/2) just until the butter is melted. Remove from heat and cool to 115 degrees (any hotter may kill your yeast). Add the yeast and honey to the pan and stir to combine.
Let sit for 10 minutes, until the mixture is frothy. Put the milk mixture into a stand mixer fitted with a dough hook and beat in the egg, cinnamon (2 teaspoons) and salt.
Add the flour, 1 cup at a time, and mix until combined before adding more. (If the dough seems firm enough, you may not need the final 1/2 cup.) Knead the mixture using the dough hook for 4-5 minutes, until the dough is springy and elastic.
Turn the dough out of the bowl and lightly oil the inside of the bowl (no need to clean the bowl first). Put the dough back in the bowl, turning to coat it a little in the oil, then cover it with plastic wrap and let it rise about 2 hours, until doubled.
Butter a glass 9 by 13 baking dish. Turn the dough out onto a lightly floured work surface and roll it into a large rectangle, about 16 inches by 12.
Spread the dough with the remaining softened butter (1/2 cup), then sprinkle with the brown sugar, being sure not to miss the edges. Sprinkle with the pecans and cinnamon (1 tablespoon), then roll up the dough from one of the long sides.
Use a serrated knife to cut 18 rolls, arranging them in the baking dish. Cover with plastic wrap and let rise in the refrigerator overnight, or for about 1 hour.
Preheat oven to 375 degrees. Bake the rolls for 18-20 minutes, until rolls are well risen and the tops are turning gold. Be careful not to overbake or they’ll dry out. Turn out onto a cooling rack, letting any extra sugar or butter drip over them.
While the rolls are cooling slightly, use a mixer to combine the frosting ingredients (1/2 cup salted butter, softened; 1/2 cup plain Greek yogurt; 2 1/2 cups confectioners’ sugar; 2 tablespoons orange juice; 1 teaspoon vanilla).
Flip the rolls over and frost while still warm. Serve at once.