Step 1

Preheat oven to 180°C. Lightly grease a 22cm square cake pan and line with baking paper.

Step 2

Combine the oil, butter and sugars in a large bowl. Whisk in the eggs and vanilla until well combined. Add the flour, cocoa, chocolate and prunes and stir until well combined. Spoon into prepared pan, sprinkle with crushed biscuits and bake for 40-45 minutes or until just firm to touch.

Step 3

Remove the pan from the oven and place on a wire rack to cool to room temperature before serving. If you prefer a firmer brownie, refrigerate until chilled and firm before serving.