-
1
Place chopped chocolate in a medium bowl, add vanilla, and suspend a large, single-mesh sieve over the top. Whisk sugar, salt, espresso powder, cocoa powder, and cornstarch together in a 3-quart stainless steel saucier. Add egg yolks and roughly 1/2 cup of the milk and whisk until smooth before adding the rest of the milk. Cook over medium-low, stirring gently with a whisk until hot to the touch; about 6 minutes.
-
2
Increase heat to medium and continue whisking gently until thick and bubbly, about 5 minutes (if it's not bubbling by then, feel free to crank up the heat). When you see that first bubble, set a timer and continue whisking exactly 90 seconds. Immediately pour into the sieve, pressing with a flexible spatula until custard passes through. Fold until chocolate has melted into the custard, and cover with a heavy towel.
-
3
Adjust oven rack to lower-middle position and preheat to 375u00b0F. Prepare Swiss Meringue as directed. Pour custard into the prepared crust, and dollop meringue over top. Gently spread it edge to edge with the back of a fork, using the tines to sculpt it into a pretty design. Place on a wire rack set inside a 13- by 18-inch rimmed baking sheet and bake until well browned, about 15 minutes (this set-up minimizes heat transfer to the custard).
-
4
Cool 1 hour at room temperature, then cover loosely in plastic and refrigerate to an internal temperature of 60u00b0F, about 3 1/2 hours. Cut with a wet chef's knife, rinsing the blade clean with cold water between each slice. Wrapped in plastic, leftovers can be refrigerated up to a week.
