While the dough rises, line the 9x13 inch pan with parchment paper.
Melt the butter and let it cool slightly, then stir in the vanilla extract and pour it into a small bowl.
In a shallow bowl, mix the brown sugar, cinnamon, and nutmeg for the coating.
Lightly oil your work surface and turn the dough out.
With oiled hands, pull off a golf ball size piece of dough. Dip it in the vanilla butter, let the excess drip off, then roll it generously in the cinnamon sugar until fully coated.
Place the coated piece in the prepared pan and repeat with the remaining dough, they will expand and connect as they proof.
Cover the pan and proof at room temperature for 1 to 2 hours, until the pieces are poofy, touching or nearly touching, and jiggle when you gently shake the pan.
During the last 30 minutes of proofing, preheat the oven to 425°F (220°C) with a rack in the center.
Just before baking, press one dimple into the top of each piece with your fingertip.
If using nuts, sprinkle the crushed walnuts or pecans evenly over the top now.
Bake for 25 to 30 minutes, until deeply golden and the center reaches 200°F (93°C). Check the bottom at about 22 minutes, and if it is coloring too quickly, slide a second baking sheet underneath for the rest of the bake.
Cool in the pan for 10 to 15 minutes before icing.