Source: Mollie Katzen’s Still Life with Menu
- butter for greasing
- 2 tablespoons butter
- 2 ounces unsweetened chocolate
- 2 cups buttermilk
- 1 teaspoon vanilla extract
- 2½ cups (11.25 oz | 318 g) unbleached all-purpose flour
- 2¼ cups packed brown sugar, divided (weight measurements in recipe)
- 3 teaspoons baking powder
- 1 teaspoon baking soda
- ½ teaspoon salt
- 1 cup semisweet chocolate chips (optional)
- ½ cup plus 2 tablespoons (1.75 oz | 48g) unsweetened cocoa
- 2½ cups boiling water
- Preheat the oven to 350°F. Butter a 9 x 13-inch baking pan.
- Melt the butter and chocolate together. (I did this in the microwave.)
- In a separate saucepan, heat buttermilk gently until just a little warmer than body temperature being careful not to boil or cook it. (Note: I barely heated my buttermilk because I was so worried about it curdling, and next time, I am going to just skip this part. I will report back.) Remove from heat and set aside.
- In a large mixing bowl combine flour, 1 cup (7.25 oz | 208 g) of the brown sugar, baking powder, baking soda, and salt. Mix well (use your hands, if necessary, to break up any little lumps of brown sugar), making as uniform a mixture as possible.
- Pour melted chocolate and butter into dry ingredients. Pour in buttermilk and vanilla. Stir until combined. Stir in chocolate chips, if desired. Spread into the prepared pan.
- Combine the remaining 1¼ cups (260 g | 9.25 oz) brown sugar with the unsweetened cocoa in a small bowl. Sprinkle this mixture as evenly as possible over the top of the batter.
- Pour on the boiling water. It will look terrible, and you will not believe you are actually doing this, but try to persevere.
- Place immediately in the preheated oven. Bake for 30 to 40 minutes (I say closer to 30 — I did 31), or until the center is firm to the touch.
- Cool for at least 30 minutes before serving. Invert each serving on a plate so that the fudge sauce on the bottom becomes a topping. Serve hot or at room temperature.