Start by turning your oven on to 350°F (175°C) so it has time to heat up. While that’s happening, prep your baking pan. If you’re using a 9×13-inch pan, just lightly grease it or line it with parchment paper. If you’re using round cake pans instead, grease and flour them—or just put parchment rounds at the bottom.

Grab a big mixing bowl. Add your sourdough discard, hot coffee, sugar, eggs, oil, and vanilla. Whisk everything together until it looks smooth and fully blended. The hot coffee helps bring out the chocolate flavor from the cocoa you’ll add in the next step, so don’t skip that.

In a different bowl, sift together your flour, cocoa powder, baking powder, and salt. Give it a quick stir to make sure everything is evenly mixed.

Now slowly add your dry ingredients into the wet mixture. Stir gently—don’t go overboard. Mix just until you don’t see any more dry spots. The batter should look smooth and a little runny, not thick.

Pour the batter into your prepared pan or pans, spreading it out evenly. Put it in the oven and bake for about 30 to 35 minutes. You’ll know it’s done when you stick a toothpick in the middle and it comes out clean or with just a few moist crumbs. Try not to overbake it, or it’ll dry out.

Once the cake’s done, take it out of the oven and set the pan on a cooling rack. Leave it in the pan for about 15 minutes, then carefully remove it and let it cool all the way before frosting it.

While the cake’s cooling, make your frosting. In a large bowl, beat the butter until it’s light and fluffy. Add the espresso powder and yogurt (or buttermilk), and mix it in well. Then gradually sift in the powdered sugar, mixing after each addition until it’s smooth. Finish by adding a bit of hot water to get the frosting to the consistency you like.

Once the cake is completely cool, spread the frosting evenly over the top. If you’re making a layer cake, frost between the layers and cover the top and sides. Slice it up and enjoy!