- cooking spray
- 1/4 cup semisweet chocolate chips
- 1 cup white sugar
- 1 egg
- 3 cups all-purpose flour
- 1 cup milk
- 1 cup unsweetened cocoa powder
- 1/2 cup sour cream
- 1 tablespoon vegetable oil
- Preheat oven to 350 degrees F (175 degrees C). Grease a 9-inch baking pan with cooking spray.
- Melt chocolate chips in a microwave-safe glass or ceramic bowl in 15-second intervals, stirring after each melting, about 1 minute. Let cool.
- Combine sugar and egg in a large bowl; beat with an electric mixer until light and airy, about 3 minutes. Add melted chocolate, flour, milk, cocoa powder, sour cream, and vegetable oil; beat until batter is smooth and well blended.
- Pour batter into the prepared baking pan.
- Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 30 minutes.