Preheat oven to 350°F.

Line bottom of a 9-inch diameter cake pan with 2-inch high sides with parchment.

Place butter, espresso and brown sugar into a medium saucepan. Place over medium heat. Stir and dissolve sugar.

Add chocolate. Whisk until melted and smooth.

Remove from heat and cool slightly.

In a separate bowl, whip eggs until blended. Stir eggs into chocolate mixture until blended. (Do not whip).

Pour chocolate batter into prepared cake pan. Place the cake pan in a roasting pan. Pour enough hot water into roasting pan to come halfway up sides of the cake pan.

Carefully place roasting pan with cake pan inside into preheated oven. Bake until center of cake is set and tester inserted into center comes out with a few moist crumbs attached, about 45 minutes. Remove from oven. Remove cake pan from water. Place in refrigerator to chill cake overnight.

Remove cake from refrigerator to a work surface.

Cut around pan sides to loosen cake. Using oven mitts, hold pan bottom over low heat for 15 seconds, warming slightly to release cake. Place platter over pan. Hold pan and platter together tightly and invert. Lift off cake pan, peel off parchment.

Dust top of cake with cocoa powder.

Cut cake into 10 slices.

Place 1 slice on a serving plate. Garnish with fresh raspberries, raspberry sauce and a scoop of caramel ice cream. Serve.