For the bacon crumble:
Preheat the oven to 180 °C. Place the bacon in a large frying pan over medium heat and cook, turning every 2–3 minutes, until crisp and golden. Finely chop the cooked bacon and then set aside.
For the brownies:
Line a 20 × 30 cm baking tin with baking paper and lightly grease. Place the chocolate and butter in a heatproof bowl and melt gently in the microwave or over a double boiler. Allow to cool slightly. In a separate bowl, whisk the eggs and castor sugar until pale and slightly thickened. Stir in the vanilla extract. Fold the melted chocolate mixture into the egg mixture. Sift in the flour, cocoa powder and salt and fold gently until just combined. Add in the roughly chopped caramel eggs or caramel-filled slab pieces. Pour the batter into the prepared tin and bake for 35–40 minutes until the edges pull slightly away from the tin but the centre remains fudgy. Allow the brownies to cool in the tin.
For the chocolate ganache:
Place the finely chopped chocolate in a heatproof bowl. Heat the cream in a small saucepan until steaming but not boiling. Pour the hot cream over the chocolate and leave to stand for 5 minutes, then stir until smooth and glossy.
To serve:
Cut the brownies into squares and arrange on a serving platter. Pour over the chocolate ganache and decorate with bacon crumble.