METHOD:

• Preheat convection oven to 325° F.
• Lightly spray two 9-inch-round cake pans with baker’s non-stick cooking spray. Line the bottoms with parchment rounds.
• Whisk the cocoa powder and 1 1/2 cups boiling water in a medium bowl until smooth; set aside.
• Whisk the flour, sugar, baking powder, baking soda and salt in a large bowl until combined.
• Add the eggs, vegetable oil, sour cream and vanilla and beat with a mixer on medium speed until smooth, about 1 minute.
• Reduce the mixer speed to low; beat in the cocoa mixture in a steady stream until just combined.
• Divide the batter between the pans.
• Bake until a toothpick inserted into the middle comes out clean, 25 to 30 minutes.
• Let cool 10 minutes, turn the cakes out onto the racks to cool completely.
• Remove the parchment.
• Frost if desired.