Traditional Layered French Croissants

INGREDIENTS:

2 tablespoons all-purpose flour
1 ½ cups unsalted butter, at room temperature
4 cups all-purpose flour, divided
½ teaspoon salt
3 tablespoons sugar
2 (.25 ounce) packages active dry yeast
¼ cup lukewarm water
1 cup milk
½ cup heavy cream
1 egg
1 tablespoon water

DIRECTIONS:

Sprinkle 2 tablespoons of flour over the butter and mix it together with your hands in a mixing bowl or on a work surface. Transfer the butter to a length of foil or parchment paper and pat it into a 6 inch square. Fold up the foil to make a packet and refrigerate until chilled, about 2 hours.
Combine 2 cups of the flour with the salt and sugar in a mixing bowl. Dissolve the yeast in the lukewarm water (100 degrees F/38 degrees C) and set aside until frothy, about 10 minutes. Meanwhile, warm the milk and the heavy cream to lukewarm. Add the yeast, milk, and cream to the flour mixture and stir well. The dough will have a batter-like consistency.
Stir in the remaining 2 cups of flour 1/4 cup at a time to form a soft dough. It should no longer be sticky. Turn the dough onto a lightly floured work surface and knead until smooth, about 5 minutes. Place the dough in a mixing bowl and cover with plastic wrap. Refrigerate for 1 hour.
To begin the rolling and folding process, both the butter and the dough should be at a cool room temperature. [See Cook’s Note.] Place the dough on a floured surface and roll it into a 10-inch square. Set the block of butter diagonally on the square dough. Bring each point of dough to the center of the butter square; the edges of the dough should overlap. Pinch the edges together to seal.
Starting from the center of the square and working outward, use a rolling pin to roll the dough out into a rectangle. The butter should be pliable enough to roll smoothly with the dough; if it’s too soft and starts to ooze out the corners, wrap the dough in plastic and refrigerate before proceeding. Roll the dough into a long rectangle, approximately 8 by 18 inches. Fold the length of dough into thirds, like a business letter …