Start by setting your oven to 350°F (175°C). While it’s heating, take an 8-inch round cake pan and line the bottom with parchment paper. Lightly grease the sides with oil or non-stick spray so the cake doesn’t stick.

Grab a large mixing bowl. Add in the almond flour, cocoa powder, baking powder, espresso powder, salt, and sugar. Stir everything together until it’s well combined and evenly mixed.

In a separate bowl, whisk together the eggs, olive oil, vanilla extract, and water. Once that mixture is smooth, pour it into the bowl with your dry ingredients. Mix just until it all comes together don’t overdo it or the texture of the cake will suffer.

Pour the batter into your prepared cake pan. Use a spatula to smooth out the top. Slide it into the oven and bake for about 28 to 32 minutes. You’ll know it’s done when a toothpick poked in the center comes out clean or with just a few moist crumbs. Let the cake sit in the pan for about 10 minutes, then turn it out onto a wire rack to cool completely.

Melt the chopped dark chocolate gently over low heat either in a saucepan or using a double boiler. Keep stirring until it’s completely smooth, then take it off the heat and let it cool slightly. In a separate large bowl, beat the butter until it’s fluffy. Add the sifted powdered sugar, the melted chocolate, and milk. Beat everything together until the frosting is creamy and smooth.

Once the cake is fully cooled, use an offset spatula or a regular one to spread the frosting evenly over the top and sides. You can keep it smooth for a clean look or create some swirls for a bit of texture and style.

Pop the finished cake into the fridge for about 20 to 30 minutes so the frosting sets. Before serving, let it sit out and come back to room temperature. You can dust the top with a bit of cocoa powder or add some shaved chocolate for a nice touch, if you like.