Use a sharp chef's knife to cut out triangles with a 2 1/2-inch base and 10-inch sides. Lay each triangle on a lightly floured work surface with the tip facing you. Gently pull the tip toward you; this light stretch adds layers to the finished croissant without adding density. Use the palms of your hands to roll each triangle up from the base to the tip. (At this stage, they can be frozen for up to 1 week if well wrapped in plastic wrap. Thaw on a parchment paper-covered baking sheet overnight in the refrigerator before proceeding.)
Place the rolled croissants on a parchment covered baking sheet; spaced about 2 inches apart. Loosely cover the baking sheet with plastic wrap. Allow the croissants to proof at room temperature until they have doubled in size and appear light and full of air; about 1 1/2 to 3 hours depending on the temperature of the room and of the dough.
Have dough rolled to the 10 by 36-inch rectangle. Use an offset spatula to spread a 1/8-inch-thick layer of almond cream over the dough, spreading it all the way to the edges of the rectangle. Sprinkle the top of the almond cream with the hydrated raisins. Roll the dough toward you, starting at the long side. Try to keep the roll tight and even. Cut the roll into 1-inch-thick slices. You will have a tail on each slice. To close the pain au raisin, simply tuck the tail under the dough. Place the pain au raisin on a parchment covered baking sheet, spaced about 2 inches apart. Allow the Pain au Raisin to proof at room temperature until they have doubled in size and appear light and full of air; about 1 1/2 to 3 hours depending on the temperature of the room and of the dough.
Courtesy of Food Network Magazine