Cake Base

1. Pre-heat oven to 180 deg C and grease a 8?X8? square tin or a 8-9? dia round tin.
2. Line the bottom with parchment. Grease the parchment too.
3. Mix almonds, cocoa, flour and salt in a small bowl.
4. Whisk eggs, sugar, oil and sour cream in a bigger bowl till the sugar dissolves.
5. Add the dry mixture into the wet and stir till just combined. Do not overwork the batter.
6. Bake for 20-25 minutes and cool in the cake tin for a half hour before turning out on the rack.
7. Line the same cake tin (washed and dried) used to bake the cake in, with cling film, making sure the film hangs over the edges of the tin. This just makes it easier to lift the mousse cake out after its frozen.
8. Place the cooled cake back into the cling-film lined tin and leave to rest in the refrigerator for a couple of hours.

Mousse

1. Melt the chocolate in the microwave in short bursts, or in a heat-proof bowl sitting over a pot of boiling water. Keep aside to cool for minute.
2. Whisk the egg yolks and pour in the warm chocolate while whisking continuously. Whisking continuously will prevent the yolks from scrambling.
3. Whisk the double cream till soft peaks form.
4. Fold the egg-chocolate mixture into the softly whipped cream. Use a large bowl for this, since the egg whites will also be folded into this later.
5. Whisk the egg whites in a separate (clean) bowl with the electric beaters on high, till the whites start foaming (this will take about a minute).
6. Start adding the sugar a teaspoon at a time while still whisking the whites, till the whites form stiff glossy peaks.
7. Take 1/3 of the whisked meringue and stir it quickly into the chocolate-cream mixture.
8. Add the rest of the meringue and the black pepper in and fold gently.
9. Pour this mousse on top of the cake and smooth out the top with a palette knife.
10. Sprinkle the top with freshly cracked black pepper.