While I did not succeed in my goal, I can at least say that now I've made my own, and nothing beats a freshly baked pain au chocolat. For this recipe you'll need croissant dough and chocolate baking sticks. I sourced mine from King Arthur Flour, but if you wanted, I bet you could just carefully line up some semi-sweet chocolate chips instead.
Pains au Chocolat (adapted from Bouchon Bakery)
1/2 recipe croissant dough, thawed but still cold
20 chocolate baking sticks
1 egg, beaten and strained (I like to thin this out a little with 1 teaspoon of water)
Spray a baking sheet with nonstick cooking spray and line with parchment paper.
Lightly flour the work surface. Roll the dough out to a rectangle about 19 x 9 inches. Trim to a 17 ½ x 8 inch rectangle. Cut the dough in half lengthwise, then cut each half into five 4 x 3 ½ inch rectangles.
Brush the pains au chocolat with egg wash. Cover the pans with plastic tubs or cardboard boxes and let proof for about 2 hours.
Preheat the oven to 350°F.
Brush the pains au chocolat again with egg wash. Bake for 35 to 40 minutes, rotating the baking sheet once halfway through baking and separating the pains if they are touching, until the tops are a rich golden brown and no portions, particularly between the layers, look undercooked. Set the baking sheet on a rack and cool completely.
*At this point I froze some of the shaped pains. The night before I wanted to eat them, I took them out of the freezer and let them thaw and proof at room temperature overnight. In the morning I brushed them with egg wash before baking as instructed above.
Next: Rainbow Sandwich Cookies
Previously: Almond Croissants
Three years ago: Sweet Potatoe Gnocchi with Maple Cinnamon Sage Brown Butter
Four years ago: Scallion Pancakes