Preheat oven to 350°. Have ready four 8oz ramekins or other oven proof bowls, a large roasting or baking pan, and a small pot of simmering water.
Place chocolate in a large heatproof bowl. Heat and stir the half-and-half, sugar, instant espresso, and salt over medium heat until mixture is hot. Pour over chocolate. Set the bowl of chocolate over the pot of simmering water and whisk until smooth.
Remove from the pot of simmering water and let the mixture cool slightly, then whisk in the egg yolks and vanilla.
Divide the mixture among the bowls and place in a roasting pan. Fill the pan with the hot water from the sauce pan, about half-way up the sides of the dishes.
Cover the pan tightly with aluminum foil and bake for about 35 minutes, or until the sides of the custards are set but the center is still wobbly.
Cool on a wire rack and serve when slightly warm, garnished with whipped cream and raspberries.