Preheat and prepare your tins: Set your oven to 180°C (160°C fan). Grease two 20cm round cake tins with butter, then line the bases with baking parchment. Dust the sides lightly with cocoa powder — this prevents a white flour residue on the finished cake.

Sift the dry ingredients: In a large bowl, sift together the flour, cocoa powder, bicarbonate of soda, baking powder, and salt. The sifting aerates the mixture and removes any lumps; you should see a fine, dark brown powder that smells deeply of chocolate.

Combine the wet ingredients: In a separate jug, whisk the sugar, oil, eggs, vanilla extract, and buttermilk until the mixture is pale and slightly thickened — about 2 minutes. The texture should be smooth and glossy, like thin caramel.

Add the coffee: Pour the cooled coffee into the wet mixture and whisk gently. The batter will become very thin and liquid — don't worry, that's exactly what we want. It should look like a milky chocolate drink.

Combine wet and dry: Pour the wet mixture into the dry ingredients and fold together with a spatula. Mix until just combined; you'll see a few small lumps disappear, but stop as soon as the flour streaks vanish. The batter will be very loose and will bubble slightly.

Divide and bake: Pour the batter evenly into the prepared tins — I use a digital scale to get exactly 500g per tin for perfect layers. Bake for 30–35 minutes. The cake is ready when the top springs back to a gentle touch, and a skewer inserted into the centre comes out with a few moist crumbs, not wet batter. The kitchen will smell intensely of rich chocolate.

Cool completely: Leave the cakes in their tins for 10 minutes on a wire rack. Then turn them out, peel off the parchment, and let them cool fully — at least 1 hour. Warm cakes will melt your ganache, so patience is essential.

Make the ganache: Place the chopped dark chocolate in a heatproof bowl. Heat the double cream in a small saucepan until it just begins to simmer — you'll see small bubbles around the edge, but do not let it boil. Pour the hot cream over the chocolate and let it sit for 2 minutes. Stir gently from the centre outward until the mixture is smooth and glossy. Add the softened butter and stir until fully incorporated. The ganache should be pourable but thick enough to coat the back of a spoon.

Assemble and glaze: Place one cake layer on a serving plate or turntable. Spoon a generous layer of ganache on top — about 3 tablespoons — and spread evenly. Place the second layer on top, then pour the remaining ganache over the centre. Use a palette knife to spread it to the edges, letting it drip naturally down the sides. For a clean finish, work quickly while the ganache is still warm.

Final touches: Allow the ganache to set for 15–20 minutes at room temperature until it is firm to the touch but still glossy. Arrange fresh raspberries in a neat cluster on top and scatter a few edible flowers for colour. The contrast of deep chocolate and bright red fruit is visually stunning.