Preheat your oven to 350°F (177°C). Place a rack in the center of the oven and another on the bottom. Grease a 9-inch round cake pan, line it with parchment paper, grease the parchment paper as well.

Place the butter and chopped chocolate into a large heat-proof bowl. Melt them together by microwaving in 20-second increments, stirring after each until smooth. Alternatively, you can use a double boiler. Once melted, set aside to cool slightly for 2-3 minutes.

Add the sugar, espresso powder, and vanilla extract to the melted chocolate mixture, whisking until smooth. Whisk in the eggs one at a time, until the mixture is smooth throughout.

Sift in the cocoa powder, salt, and baking powder, stirring until just combined. Avoid overmixing.

Pour the batter into the prepared cake pan and spread it evenly. Tap the pan lightly on the counter to remove air bubbles.

Set a large metal roasting pan or baking dish (not glass) on the bottom oven rack. Carefully pour in boiling water so it reaches about 2 inches up the side of the pan. Quickly place the cake pan on the center rack and shut the oven door.

Bake for 28-32 minutes, or until the edges are set and a toothpick inserted in the center comes out with moist crumbs or clean. Check at the 25-minute mark to avoid overbaking. A slight rise and cracking around the edges are normal and will flatten as it cools.

Remove the cake from the oven and cool in the pan on a cooling rack for 10 minutes. Gently run a thin knife around the edges to help loosen the cake. Carefully invert it onto a serving plate. If it cools completely in the pan, it may be difficult to remove. Allow the cake to cool completely.

Before serving, dust the top with powdered sugar and fresh raspberries. Enjoy!