01 -
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, and grease the parchment paper as well.
02 -
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, use a double boiler. Allow to cool slightly for 2-3 minutes.
03 -
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 fully combined and smooth.
04 -
Sift in the cocoa powder, salt, and baking powder, stirring until just combined. Avoid overmixing for best texture.
05 -
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 on the bottom oven rack, fill with boiling water until 2 inches deep, and place the cake pan on the center rack above. Bake for 28-32 minutes, or until edges are set and a toothpick inserted in the center comes out with moist crumbs or clean.
06 -
Remove the cake from the oven and cool in the pan on a cooling rack for 10 minutes. Run a thin knife around the edges to loosen the cake and invert it onto a serving plate. If cooled completely in the pan, it may stick. Allow to cool fully.
07 -
Dust the top of the cake with powdered sugar and garnish with fresh raspberries before serving.