In a small bowl, whisk together the cocoa powder, vanilla extract and boiling water until smooth. Set aside to cool slightly.
In a large bowl, beat the caster sugar, eggs and olive oil together for 3 minutes or until pale, creamy and slightly thickened.
With the beaters running on low, slowly pour in the cocoa powder liquid. Continue mixing until well combined.
Add the almond meal, bicarbonate of soda and the pinch of salt. Mix on low until combined.
Pour the mixture into the prepared tin and bake for 40 minutes or until a skewer inserted into the middle comes out with just a few moist crumbs on it.