Fluffy and tender, this chocolate cake comes together quickly in one bowl. It’s a friendly little birthday cake with its dead simple frosting (or a really great snack without). A blend of oil and buttermilk or yogurt keeps the crumb moist, as does a nice pour of hot tea. Oolong gives the cake a floral aroma, while using coffee instead highlights the cocoa’s bittersweetness. Plain hot water gives this an old-fashioned chocolate cake flavor. The two-ingredient frosting – essentially cream and chocolate melted together, then cooled until thick enough to swoop and swirl – can be made in the same bowl used for the cake batter. You can sprinkle flaky salt, chopped toasted nuts or sprinkles on top too. But, frosted or not, this cake welcomes coffee, tea or ice cream.

One-Bowl Chocolate Cake
Ingredients for the cake:
• Canola or vegetable oil, for greasing the pan
• 1 1/4 cups/163 grams all-purpose flour
• 1 1/4 cups/250 grams sugar
• 1/2 cup/54 grams unsweetened natural cocoa powder
• 1 teaspoon baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon fine salt
• 2 large eggs
• 1/2 cup/189 grams buttermilk or plain full-fat yogurt
• 1/4 cup/60 grams canola or vegetable oil
• 1 teaspoon vanilla extract
• 1/2 cup hot oolong or black tea, hot coffee or hot water

Ingredients for the frosting (optional):
• 1 (4-ounce) bar bittersweet or semisweet chocolate, broken into small pieces
• 1/2 cup/125 grams heavy cream

Directions:
Make the cake: Heat oven to 350 degrees. Rub oil all over an 8-inch square cake pan.

Whisk the flour, sugar, cocoa powder, baking powder, baking soda and salt in a large bowl. Add the eggs, buttermilk, oil and vanilla, and stir with the whisk until smooth. It will be thick at this point; gently smack the whisk against the bowl to release any batter stuck inside.

Add the hot tea and whisk until very smoth. Switch to a flexible spatula and scrape all of the batter into the pan.

Bake until a toothpick inserted in the center comes out with a few tiny crumbs, about 45 minutes. Cool completely in the pan on a rack.

If you’re making the frosting, start it as soon as the cake comes out of the oven: Use the same bowl you used for the batter, washing it if you want. Combine the chocolate and cream in the bowl and microwave for 30 seconds. Stir well, then microwave for 15 seconds and stir until smooth. If some chocolate remains solid, zap for 10 more seconds and stir.

If you don’t have a microwave or microwave-safe bowl, set the bowl over a saucepan of barely simmering water and stir until smooth.
Let the chocolate cream cool, stirring now and then, until thickened to the consistency of soft frosting. (This may take up to an hour.) Plop it all over the cake, even if it’s still a touch warm, and use a flexible spatula or a large spoon to swoop and swirl it to cover the top. Cut into pieces and serve.

Total time: 2 hours, mainly cooling, makes one 8-inch cake (9 to 12 servings).