CINNAMON CROISSANT COFFEE CAKE (PRINCESS RING)

Steps:

• Prepare ring:
• Butter a 24-centimeter (about 9-inch) springform pan and line with a round of parchment paper. Butter paper and remove side of pan.
• Stir together sugars and cinnamon.
• Roll out dough on a lightly floured surface, dusting with flour as necessary, into a 24- by 9-inch rectangle. Brush off excess flour with pastry brush and trim edges with a pizza wheel or sharp knife.
• Arrange dough so that a long side is nearest you and sprinkle cinnamon sugar over dough, leaving a 1-inch border along bottom edge. Brush border with some beaten egg and chill remaining egg. Fold top edge of dough over about 1 inch. Using both hands, roll dough toward you: Use your thumbs to tuck dough under and tighten as you go, working your way down entire length of log (as when rolling up a poster), and gently rock dough back and forth to keep it taut and even. When finished, roll log back and forth over seam to seal.
• Transfer log, seam side down, to bottom of springform pan, bringing both ends of log together to make a ring. Beginning 2 inches from where ends meet, make vertical cuts from outside of ring toward center at 2-inch intervals, cutting halfway through ring.
• Let ring rise:
• Attach side of pan and slide pan into garbage bag, propping up top of bag with inverted glasses to keep it from touching dough, then tuck open end under pan. Let ring rise until slightly puffy and spongy to the touch, about 2 1/2 hours.
• Make streusel while ring is rising:
• Blend flour and sugar in a food processor. Add frozen butter and pulse until very finely chopped. Chill streusel until ready to use.
• Preheat oven to 375°F.
• Gently brush top and center of ring with some of remaining beaten egg, then sprinkle with streusel. Bake in middle of oven until top is browned and streusel is crisp, about 45 minutes.
• Cool in pan on a rack 10 minutes, then run a thin knife around edge to loosen and remove side of pan.