Cinnamon swirls are a delicious alternative for those who do not like raisins or other dried fruits. They are made up, proofed, and baked in exactly the same way as pain aux raisins. I mix my crème pâtissière with cinnamon sugar, to make the cinnamon custard. This beautiful cinnamon custard is at the heart of these delicious cinnamon swirls. They are sprinkled on the top with crushed sugar just before baking. Otherwise, the sugar will dissolve on the egg wash, and turn to syrup, which will run to the bottom of the pastry and burn it as it bakes. For extra crunchiness, nibbed or crushed sugar can be added just before baking.
A full recipe and more tips are available in my book, The Art of Lamination: Advanced Technical Laminated Pastry Production.