This rich flourless cake pairs deep chocolate with bright orange for an elegant dessert. Silky ganache and fluffy orange cream make every bite feel special.
Heat the oven to 325 F. Grease an 8-inch springform pan, line the bottom with parchment paper and wrap the outside securely with foil.
Melt the bittersweet chocolate and butter together over low heat, stirring until smooth. Remove from the heat and stir in the cocoa powder, orange zest, vanilla and salt.
Beat the eggs and granulated sugar for 4 to 5 minutes, until pale, thick and tripled in volume. Gently fold in the chocolate mixture in three additions.
Pour the batter into the pan and bake for 30 to 35 minutes, until the edges are set and the center remains slightly soft. Cool completely, then refrigerate for 2 hours before releasing the cake from the pan.
Heat the cream for the ganache until steaming and pour it over the chocolate, corn syrup and orange zest. Let it stand for 2 minutes, then stir until glossy and cool until slightly thickened.
Spread the ganache over the chilled cake, allowing a small amount to flow down the sides. Refrigerate for 30 minutes to set.
Beat the mascarpone, heavy cream, powdered sugar, orange zest and vanilla to firm peaks. Spoon the orange cream over the cake and finish with shaved dark chocolate.