Preheat oven to 180°C (160° fan-forced). Grease and line a loaf pan (20cm x 11cm) with baking paper.
Place butter, sugar, eggs, sour cream, lemon zest and juice in a bowl and whisk to combine. Add flour, almond meal and cocoa, whisk until well combined.
Cut 3 pieces of the sliced pears in half lengthways; set aside for the top. Coarsely chop remaining pears and fold through cake batter. Spoon into prepared pan then place the cut slices on top.
Bake for 1 hour 30 minutes or until cooked when tested with a skewer. Allow to cool before transferring to a wire rack.