Could the Emperor conceivably have had these in mind when he contended that “an army marches on its stomach”? A classic napoleon, or mille-feuille (thousand-leaf), is made up of 3 layers of puff pastry filled with vanilla pastry cream. Serve the napoleon within a few hours of making it. If you make the napoleons with saved puff pastry scraps, you do not need to weight the layers during baking. For an easier approach, see Phyllo Napoleons.

Prepare and chill:

Roll out to a 17 ½ × 13 ½-inch rectangle ¹⁄₁₆ to ⅛ inch thick:

Transfer the pastry to an ungreased baking sheet. Prick it all over with a fork. Cover and refrigerate for at least 30 minutes, or wrap airtight and freeze until ready to use.

If the dough is frozen, let it thaw for a few minutes before trimming. Transfer the dough to a cutting board and trim the sides to make a 16 × 12-inch rectangle. Return it to the baking sheet and the refrigerator while the oven preheats.

Position a rack in the lower third of the oven. Preheat the oven to 400°F.

Invert a wire rack and place it directly on the dough to prevent it from rising in the oven while baking. Bake for 10 minutes, remove the rack and prick the pastry all over, then replace the rack and bake until golden brown, 10 to 15 minutes more. Remove the rack for the final 2 to 3 minutes to dry and cook the top layers. Slide the pastry onto a wire rack and let cool.

Using a sharp serrated knife, saw the pastry gently lengthwise into 3 equal strips. Brush 2 of the strips with:

Spread half of the pastry cream over one of the (jam-covered) pastry strips. Place the second (jam-covered) piece on top and cover with the remaining pastry cream. Turn the last puff pastry strip upside down and place it over the pastry cream. Refrigerate until ready to serve, but no longer than 6 hours.

Use a sharp serrated knife and a sawing motion to cut the napoleon into individual servings. Dust the top of each serving with: