For the Cronut Pastry Dough: Combine the bread four, salt, sugar, yeast, water, egg whites, butter and cream in a stand mixer fitted with a dough hook.
Cover with plastic wrap pressed directly on the surface of the dough to prevent a skin from forming. Proof the dough in a warm spot until doubled in size, 2-3 hours.
Draw a 7 inch square on a piece of parchment paper with a pencil. Flip the parchment then place the butter in the center of the square and spread it evenly.
Remove the plastic wrap and punch down the dough by folding the edges into the center, releasing as much of the gas as possible.