01 -
Preheat oven to 350°F. Position racks at center and bottom levels. Grease a 9-inch round cake pan, line with parchment paper, and grease parchment paper thoroughly.
02 -
Combine butter and chopped chocolate in a heatproof bowl. Melt using microwave in 20-second intervals, stirring until smooth; alternatively, use a double boiler. Let cool 2-3 minutes.
03 -
Incorporate granulated sugar, espresso powder, and vanilla extract into melted chocolate. Whisk until uniform.
04 -
Whisk eggs in one at a time until fully blended and smooth.
05 -
Sift cocoa powder, salt, and baking powder into mixture. Fold gently until just combined to preserve texture.
06 -
Transfer batter evenly into prepared pan. Tap pan on counter gently to release air bubbles. Place a large roasting pan on bottom oven rack, fill with boiling water up to 2 inches deep, and position cake pan on center rack above.
07 -
Bake for 28 to 32 minutes, until edges are set and a toothpick inserted in the center comes out with moist crumbs or clean.
08 -
Remove cake from oven and cool in pan on rack for 10 minutes. Run a thin knife around edges to loosen and invert onto serving plate carefully. Allow to cool completely to avoid sticking.
09 -
Dust top with powdered sugar and adorn with fresh raspberries prior to serving.