Adjust the oven rack to the middle position and heat the oven to 425 degrees. Line a heavy baking sheet with parchment paper. Fit a large (at least 14-inch) pastry bag with a ⅝-inch (17-mm) plain round tip. Twist the bag just above the tip (fig. 1.1) and push it into the tip to prevent the paste from dribbling out when you load the bag. Fold over the open end to form a cuff and hold the bag under the cuff with one hand.vLoad the choux paste into the pastry bag with a rubber spatula (fig. 1.2). When scraping out the bowl with just one hand becomes cumbersome, set the bag tip-side down in a tall drinking glass; the glass will support the bag as you continue to fill it. Unfold the cuff, lay the bag on its side, and use a small metal spatula to scrape the paste toward the tip of the bag (fig. 1.3).

Use small dabs of choux paste left in the bowl or on the spatula to glue the corners of the parchment paper to the baking sheet. Gather up and twist the wide end of the bag, unwind the knot from the tip end, and pipe twenty-four 2-inch rounds of paste in six rows of four. Try to pipe the mounds high and round (fig. 2.1). Sprinkle each mound with about ½ teaspoon of sanding sugar, if using (fig. 2.2).

Bake for 15 minutes, until the mounds have puffed impressively and colored lightly; do not open the oven door during this time. Lower the oven temperature to 350 degrees and continue baking until the puffs are deep golden, about 20 minutes more. Remove the baking sheet from the oven (close the oven door) and quickly pierce the side of each profiterole with a chopstick or wooden skewer to allow steam to escape (fig. 3.1); handle the pastries gently, as they are quite delicate. Return the baking sheet to the oven, turn off the oven, and prop open the door with the handle of a wooden spoon. Allow the profiteroles to dry in the vented oven for 10 minutes, and then close the oven door completely and let dry for 1½ hours (fig. 3.2). In low humidity conditions, the puffs can be held for up to 4 hours at room temperature before serving.

Using a small serrated knife, carefully cut in half along the equator as many profiteroles as you’d like (two per person is a good baseline). If using confectioners’ sugar, set the lids on the baking sheet and use a fine-mesh strainer to sift confectioners’ sugar over them. Spoon or ladle Strawberry Syrup or Hot Fudge Sauce onto individual serving plates and place the pastry bottoms on top of the sauce. Scoop Chantilly meringue onto the pastry bottoms, replace the tops, and serve.