Combine the rich layers of a croissant with the sweet swirls of a cinnamon bun and you’ll have one of our favorite brunch pastries: morning buns. For a simpler route to a yeasted, croissant-like pastry, we added a packet of yeast to a quick puff pastry dough. We created long, thin pieces of flake-producing butter by adding chilled butter to the dry ingredients in a zipper-lock bag and rolling over it with a rolling pin.