Step 1

Heat the oven to 425°F. Line a baking sheet with parchment or baking mats.

Step 2

Make the pâte à choux: Prepare the pâte à choux following these instructions.

Step 3

Pipe the pâte à choux into eclair shapes: Transfer the prepared pâte à choux to a piping bag fit with a large round tip, or transfer to a zip-top bag and snip off the end. Pipe small finger-length eclairs or larger, double-wide eclairs, as desired.

Step 4

Bake the eclair shells: Bake for 12 to 15 minutes, until puffed. Without opening the oven, turn down the temperature to 375°F and bake for another 18 to 20 minutes, until golden-brown and dry to the touch. Lower the heat again to 300°F, and let the eclair shells dry out for another 15 minutes. Remove from the oven, pierce with a toothpick, and cool completely. (The shells can be kept in an airtight container for a few days, or frozen for up to 3 months.)

Step 5

Make the pastry cream: Prepare the pastry cream following these instructions. Use the pastry cream as soon as its chilled, or refrigerate for up to three days. Make sure to press a piece of plastic wrap against the surface of the pastry cream to prevent a skin from forming.

Step 6

Fill the eclairs with pastry cream: Poke a hole into either end of the eclair using a pastry tip or a chopstick. Transfer the pastry cream to a piping bag fit with a large round tip. Insert the tip of the pastry bag into one end of the eclair and fill part way. Insert the pastry bag into the other end and fill the second half. Repeat with all the eclair shells.

Step 7

Make the chocolate glaze: Transfer the chocolate to a heatproof bowl. Warm the milk in the microwave or on the stovetop until it's steaming, then pour it over the chocolate. Let it stand for a minute or two, then stir to form a thick, glossy glaze.

Step 8

Dip the eclairs in chocolate: Dip the tops of the eclairs in chocolate. Set them on a cooling rack and top with sprinkles, if using. Allow the glaze to set. Eclairs are best eaten on the same day they are made.