1. Preheat oven to 350°F (175°C). Grease and line a 9-inch round cake pan with parchment paper.
2. Melt dark chocolate and butter together using a double boiler or microwave in 20-second bursts. Stir until smooth.
3. In a large bowl, whisk sugar and eggs until light and fluffy.
4. Add the melted chocolate mixture, whisking continuously.
5. Stir in orange zest, orange juice, and vanilla extract.
6. Gently fold in almond flour, baking powder, and salt until combined.
7. Pour batter into the prepared cake pan and bake for 30-35 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
8. Let the cake cool in the pan for 10 minutes, then transfer to a wire rack.
9. Serve as is or garnish with powdered sugar, chocolate ganache, or sliced almonds.

Storage & Serving Tips:

• Store at room temperature for up to 3 days or refrigerate for up to 5 days.
• Freeze slices for up to 2 months and thaw before serving.
• Serve with whipped cream, vanilla ice cream, or espresso for a perfect pairing.