Prepare the Raspberry Compote:

1. Cook the Raspberries: In a small saucepan, combine the raspberries, sugar, and lemon juice. Cook over medium heat, stirring occasionally, until the raspberries break down and the mixture thickens, about 10 minutes.
2. Strain the Compote (Optional): For a smoother compote, strain the mixture through a fine sieve to remove the seeds. Let the compote cool to room temperature.

Prepare the Chocolate Bavarois:

3. Melt the Chocolate: In a heatproof bowl, melt the dark chocolate over a double boiler or in the microwave in 20-second intervals, stirring until completely smooth. Let the melted chocolate cool slightly.
4. Prepare the Gelatin: In a small bowl, sprinkle the powdered gelatin over 2 tablespoons of cold water and let it bloom for 5 minutes.
5. Make the Custard: In a saucepan, heat the milk and 1/2 cup of heavy cream over medium heat. In a separate bowl, whisk together the egg yolks and sugar. Slowly pour the hot milk and cream into the egg yolk mixture, whisking constantly to temper the eggs.
6. Thicken the Custard: Return the mixture to the saucepan and cook over low heat, stirring constantly, until it thickens enough to coat the back of a spoon. Remove from heat and stir in the bloomed gelatin until completely dissolved.
7. Combine with Chocolate: Add the melted chocolate to the custard mixture and stir until fully incorporated. Let the mixture cool to room temperature.

Whip the Cream and Assemble:

8. Whip the Cream: In a separate bowl, whip the remaining heavy cream (1 cup) to soft peaks.
9. Fold in the Cream: Once the chocolate mixture has cooled, gently fold in the whipped cream until the mixture is smooth and well combined.
10. Pour into Molds: Spoon the chocolate bavarois mixture into individual molds or one large mold, smoothing the top with a spatula.
11. Chill: Refrigerate the bavarois for at least 5 hours, or overnight, until fully set.

Serve:

12. Serve with Raspberry Compote: Once set, gently unmold the bavarois and serve with a spoonful of the raspberry compote on top. Garnish with fresh raspberries or chocolate shavings if desired.