Devil's Food Cake

Preheat oven to 350 degrees F (325 if you have a small double oven). Grease your cake pans, line the bottoms with parchment paper, grease the parchment and flour the pans. Set aside.

Whisk together the cocoa powder, espresso powder if using, and hot water until smooth.

In a medium bowl, stir together the flour, baking soda, baking powder, and salt. Set aside.

Using an electric mixer, cream the butter, oil, and sugars on medium speed for 3 minutes, until light and fluffy.

On low speed, add the eggs, one at a time. Add the oil and vanilla and beat until well mixed, scraping down the bowl with a rubber spatula.

Add the chocolate mixture to the batter and mix.

Slowly add half of the flour mixture to the batter, then all of the sour cream, then the remaining flour mixture, mixing each addition until combined. With a rubber spatula, scrape down the sides of the bowl and make sure the batter is well mixed.

Put in a sieve over a large bowl and push through to get out any remaining undissolved flour.

Divide the batter evenly between the two prepared pans and smooth the tops.

Bake for 30 to 40 minutes, or until a toothpick inserted into the center comes out clean AND the cake feels slightly firm and springy when gently pushed.

Cool in the pans for 30 minutes, then turn the cakes out onto a wire rack and cool completely.