Start by preheating the oven to 175℃/ 347℉ and line a 15cm/23cm springform pan with some olive oil or cooking spray and line the base with baking paper. Note: the size of the springform pan doesn't matter - the only difference it yields is the height of the chocolate cake.
In a medium sized jug or bowl add the cocoa powder, shot of espresso, 1/3 cup boiling water together. Mix until the cocoa powder has dissolved. Set aside to cooldown. Note: you can replace the espresso with instant coffee if you'd like. Just remember to add an additional 60ml to the paste.
In a medium sized bowl, whisk the sugar and eggs together until fluffy and pale in colour, about 2-3 minutes. Add the olive oil while whisking.
Add the slightly cooled cocoa mixture and whisk until well combined followed by vanilla paste.
Add the bicarbonate soda, baking powder, salt and flour of choice: 165g/1 1/2 cups almond flour; 145g/1 cup lightly packed regular flour; 145g/1 cup lightly packed gluten free flour. Mix until well combined. Note: do not overmix.
Pour into the lined springform cake tin and bake for 45 minutes. Once baked, remove the sponge from the oven and allow to reach room temperature in the baking tin. Note: if you are using a 15cm springform pan then add additional 5 minutes baking time.
Once cooled, unclip the springform pan, and flip onto your hand (widspread) and remove the tin base and baking paper. Gently place a plate on top of the cake and flip onto the plate.
Garnish with a dusting of powdered sugar and fresh berries or melted chocolate - you decide! It's divine as is but welcomes a little dress up.