Pre-heat the oven to 175°C (350℉). Grease two 7" / 18cm pans (I also lined the bottoms with baking paper).
Using a food processor or whisk, mix the flour, sugar, cocoa, baking soda, baking powder, together until combined.
Add the eggs, Greek yoghurt, milk, oil, and vanilla.
Mix the hot water and coffee together and add to the mixture.
Beat on a medium speed until smooth. This should take just a couple of minutes.
Divide the batter equally between the two pans, and then bake for around 35-40 minutes (start checking at around the 30 minute mark). The cake is ready when an inserted skewer comes out clean.
Cool for around 15 minutes in the pans, then turn out onto a wire rack and allow to cool completely.