Step 1

Preheat the oven to 350F and grease the inside of an 8” round cake pan and line the bottom with parchment paper. This recipe also works with a 9” springform pan, but I like a thicker cake so 8” is my preference.

Step 2

In a large bowl, whisk together the flour, powdered sugar, cocoa powder, baking soda, baking powder, and salt.

Step 3

In a 2 cup measuring glass, beat together the olive oil, sour cream, egg, egg yolk, and vanilla. Pour into the bowl of dry ingredients and whisk just until it’s about halfway combined, then pour in the hot water and fully whisk to create a smooth and glossy batter.

Step 4

Pour into your pan and spread even. For 8”, bake for 35-40 minutes and for 9”, 30-35 minutes. It’s done when it’s well puffed and a toothpick in the center comes out clean with a few moist crumbs.

Step 5

Allow the cake to cool in the pan for about 20 minutes, then release and cool on a wire rack for another 20-ish minutes, just until it’s barely warm.

Step 6

Once the cake is the right temperature, make the frosting by microwaving the chocolate and oil in 30 second intervals until smooth. It shouldn’t take more than 90 seconds total.

Step 7

Then mix in the sour cream and maple syrup. It should turn glossy and fudgy but perfectly spreadable.

Step 8

Pour onto the very center of the cake and use a spoon to spread it out towards the edges, creating deep swirls throughout.

Step 9

Top with some finely chopped nuts, if desired, and enjoy! It’s the absolute best when it’s just barely warm.

Step 10

Otherwise, it will keep at room temperature for a couple days or store covered in the refrigerator for up to 5 days. I recommend bringing to room temperature or even microwaving for 15-30 seconds to revive that delicious warm texture. Enjoy!