Preheat the oven to 180˚C/160˚C fan/gas mark 6 and grease and line two 20cm cake tins.
Sift the flour, sugar, cocoa powder, baking powder, salt and coffee powder into a mixing bowl.
In a separate bowl, beat the eggs, buttermilk, oil and vanilla extract. Gradually beat into the flour mixture until combined.
Transfer to the prepared tins and bake for 30-40 minutes until a skewer inserted into the centre comes out clean. Leave to cool in the tins for a few minutes, then transfer to a wire rack to cool completely.
Melt the dark chocolate for the filling in a bowl over a saucepan of simmering water. Remove from the heat and stir until smooth. Leave to cool slightly.
Beat the icing sugar and butter together until light and fluffy. Beat in the vanilla and cooled chocolate until smooth.
Heat the Avonmore cream in a saucepan over a low heat. When bubbles start to form at the sides, remove it from the heat and pour it over the chopped chocolate, stirring until smooth.
Place one of the cooled cakes on a wire rack over a baking tray. Pour over the smooth chocolate topping, spreading it to the sides.
Place the other cake on a serving plate. Pipe the fluffy buttercream filling over in dollops. Place the other cake with the chocolate topping on top. Decorate with mini speckled chocolate eggs and serve with Avonmore Fresh Dessert Cream.