Preheat the oven to 350˚F and line the bottom of a 9-inch cake pan with parchment paper, then spray with nonstick baking spray.
In a large bowl, whisk together flour, sugar, cocoa powder, espresso powder, baking powder, baking soda, and salt.
In a separate medium bowl, whisk together olive oil, milk, eggs, and vanilla extract.
Add the wet ingredients to the dry ingredients and fold together until combined. Add the hot water and mix until combined. Scraped into the prepared pan, smoothing the batter into an even layer.
Bake for 30 to 35 minutes, or until a toothpick inserted in the center comes out clean.
Notes
Storage:Let the cake fully cool before storing it in an airtight container at room temperature for a few days. For longer storage, you can transfer the cake to the refrigerator for up to 5 days.Tips: Start with room-temperature eggs. The yolks are softer at room temperature and, therefore, much easier to incorporate into the batter.Don't overmix the batter. When combining the dry and wet ingredients, fold gently until just combined. Overmixing can lead to a dense and tough cake.Sift dry ingredients if time permits.Though optional, sifting the dry ingredients together can help remove any lumps, resulting in a lighter batter consistency. It also helps you to avoid overmixing the batter.Check for doneness. Use a toothpick or a cake tester to check for doneness. Insert into the center of the cake and if it comes out clean or with a few crumbs, the cake is ready.Cool the cake first. Let it cool for 10 minutes before transferring it to a wire rack to cool completely. This helps the cake to set properly and will be easier to remove from the pan.